Borka, Duško

Link to this page

Authority KeyName Variants
orcid::0000-0001-9196-4515
  • Borka, Duško (87)
Projects
Gravitation and the large scale structure of the Universe Functional, Functionalized and Advanced Nanomaterials
Natural Sciences and Engineering Research Council of Canada COST Action [CA15117]
Physics of collisions and photo processes in atomic, (bio)molecular and nanosized systems Physical processes in the synthesis of advanced nanostructured materials
Astrophysical Spectroscopy of Extragalactic Objects Bilateral Cooperation between Serbia and Italy [451-03-01231/2015-09/1]
COST Action [MP1304] INFN sezione di Napoli [Iniziative Specifiche QGSKY]
INFN sezione di Napoli [Iniziative Specifiche TEONGRAV] Atomic collision processes and photoacoustic spectroscopy of molecules and solids
Ministry of Science and Technological Development of the Republic of Serbia [141013] NASA at NCCU (Durham, NC, USA) [NNX09AV07A]
Natural Sciences and Engineering Research Council of Canada [249506-2011] NSF at NCCU (Durham, NC, USA) [HRD-0833184]
NSF [HRD-0833184] RFBR at ICAD of RAS (Moscow) [14-02-00754A]
Bilateral Austrian-Serbian project "Interaction of charged particles with capillaries" [451-03-01039/2015-09/25] Bilateral cooperation between Serbia and Italy (451-03-01231/2015-09/1 “Testing Extended Theories of Gravity at different astrophysical scales”)
Bilateral cooperation between Serbia and Italy [451-03-01231/2015-09/1 "Testing Extended Theories of Gravity at different astrophysical scales"] Chinese Academy of Sciences [2017VMA0014]
Chinese Academy of Sciences, NSF [HRD-0833184], NASA at NASA CADRE Center (NCCU, Durham, NC, U.S.A.) [NNX09AVO7A], NASA at NSF CREST Center (NCCU, Durham, NC, U.S.A.) [NNX09AVO7A] COST Action (CA15117 - CANTATA)
COST Action [CA15117 (CANTATA)] COST Action MP1306 “Modern Tools for Spectroscopy on Advanced Materials: a European Modeling Platform”
COST Action [MP1306], Natural Sciences and Engineering Research Council of Canada [249506-2011] COST Action [MP1306], Natural Sciences and Engineering Research Council of Canada [249506-2011], Spanish MINECO [MAT2015-65356-C3-3-R], Spanish MINECO through the Maria de Maeztu Programme for Units of Excellence in RD [MDM-2014-0377]
European COST Actions [CA15107] European COST Actions [MP1306]

Author's Bibliography

Constraining theories of gravity by fundamental plane of elliptical galaxies

Capozziello, Salvatore; Borka Jovanović, Vesna; Borka, Duško; Jovanović, Predrag

(2020)

TY  - JOUR
AU  - Capozziello, Salvatore
AU  - Borka Jovanović, Vesna
AU  - Borka, Duško
AU  - Jovanović, Predrag
PY  - 2020
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/8951
AB  - We show that fundamental plane of elliptical galaxies can be used to obtain observational constraints on metric theories of gravity. Being it connected to global properties of ellipticals, it can fix parameters of modified gravity. Specifically, we use fundamental plane to constrain modified theories of gravity with Yukawa-like corrections which commonly emerge in the post-Newtonian limit. After giving examples on how these corrections are derived, we first analyze the velocity distribution of elliptical galaxies comparing theoretical results of modified gravity with Yukawa-like corrections with astronomical data. According to these results, it is possible to constrain the parameters of the corrections discriminating among classes of models compatible with astronomical observations. We conclude that fundamental plane can be used as a standard tool to probe different theories of gravity in the weak field limit.
T2  - Physics of the Dark Universe
T1  - Constraining theories of gravity by fundamental plane of elliptical galaxies
VL  - 29
SP  - 100573
DO  - 10.1016/j.dark.2020.100573
ER  - 
@article{
author = "Capozziello, Salvatore and Borka Jovanović, Vesna and Borka, Duško and Jovanović, Predrag",
year = "2020",
url = "https://vinar.vin.bg.ac.rs/handle/123456789/8951",
abstract = "We show that fundamental plane of elliptical galaxies can be used to obtain observational constraints on metric theories of gravity. Being it connected to global properties of ellipticals, it can fix parameters of modified gravity. Specifically, we use fundamental plane to constrain modified theories of gravity with Yukawa-like corrections which commonly emerge in the post-Newtonian limit. After giving examples on how these corrections are derived, we first analyze the velocity distribution of elliptical galaxies comparing theoretical results of modified gravity with Yukawa-like corrections with astronomical data. According to these results, it is possible to constrain the parameters of the corrections discriminating among classes of models compatible with astronomical observations. We conclude that fundamental plane can be used as a standard tool to probe different theories of gravity in the weak field limit.",
journal = "Physics of the Dark Universe",
title = "Constraining theories of gravity by fundamental plane of elliptical galaxies",
volume = "29",
pages = "100573",
doi = "10.1016/j.dark.2020.100573"
}
Capozziello, S., Borka Jovanović, V., Borka, D.,& Jovanović, P. (2020). Constraining theories of gravity by fundamental plane of elliptical galaxies.
Physics of the Dark Universe, 29, 100573.
https://doi.org/10.1016/j.dark.2020.100573
Capozziello S, Borka Jovanović V, Borka D, Jovanović P. Constraining theories of gravity by fundamental plane of elliptical galaxies. Physics of the Dark Universe. 2020;29:100573
Capozziello Salvatore, Borka Jovanović Vesna, Borka Duško, Jovanović Predrag, "Constraining theories of gravity by fundamental plane of elliptical galaxies" Physics of the Dark Universe, 29 (2020):100573,
https://doi.org/10.1016/j.dark.2020.100573 .
1
6
4
5

Observational tests of general relativity and alternative theories of gravity with Galactic Center observations using current and future large observational facilities

Zakharov, Alexander F.; Jovanović, Predrag; Borka, Duško; Borka Jovanović, Vesna

(2020)

TY  - JOUR
AU  - Zakharov, Alexander F.
AU  - Jovanović, Predrag
AU  - Borka, Duško
AU  - Borka Jovanović, Vesna
PY  - 2020
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/8826
AB  - It is established that there are supermassive black holes in centers of galaxies. A supermassive black hole with mass around 4 × 106 M⊙ is located at the Galactic Center. Such an approach for the Galactic Center looks rather natural, in spite of that consequences of model must be checked with observa- tions. We discuss opportunities to check this with forthcoming observations of shadows in mm band for the Galactic Center as it was done recently for M87*. Observations of bright stars moving near the Galactic Center gives another op-portunity to evaluate gravitational potential. We discuss opportunities to use these observations to constrain alternative theories of gravity. © 2020, Astronomical Institute, Slovak Academy of Sciences.
T2  - Contributions of the Astronomical Observatory Skalnaté Pleso
T1  - Observational tests of general relativity and alternative theories of gravity with Galactic Center observations using current and future large observational facilities
VL  - 50
IS  - 1
SP  - 203
EP  - 218
DO  - 10.31577/caosp.2020.50.1.203
ER  - 
@article{
author = "Zakharov, Alexander F. and Jovanović, Predrag and Borka, Duško and Borka Jovanović, Vesna",
year = "2020",
url = "https://vinar.vin.bg.ac.rs/handle/123456789/8826",
abstract = "It is established that there are supermassive black holes in centers of galaxies. A supermassive black hole with mass around 4 × 106 M⊙ is located at the Galactic Center. Such an approach for the Galactic Center looks rather natural, in spite of that consequences of model must be checked with observa- tions. We discuss opportunities to check this with forthcoming observations of shadows in mm band for the Galactic Center as it was done recently for M87*. Observations of bright stars moving near the Galactic Center gives another op-portunity to evaluate gravitational potential. We discuss opportunities to use these observations to constrain alternative theories of gravity. © 2020, Astronomical Institute, Slovak Academy of Sciences.",
journal = "Contributions of the Astronomical Observatory Skalnaté Pleso",
title = "Observational tests of general relativity and alternative theories of gravity with Galactic Center observations using current and future large observational facilities",
volume = "50",
number = "1",
pages = "203-218",
doi = "10.31577/caosp.2020.50.1.203"
}
Zakharov, A. F., Jovanović, P., Borka, D.,& Borka Jovanović, V. (2020). Observational tests of general relativity and alternative theories of gravity with Galactic Center observations using current and future large observational facilities.
Contributions of the Astronomical Observatory Skalnaté Pleso, 50(1), 203-218.
https://doi.org/10.31577/caosp.2020.50.1.203
Zakharov AF, Jovanović P, Borka D, Borka Jovanović V. Observational tests of general relativity and alternative theories of gravity with Galactic Center observations using current and future large observational facilities. Contributions of the Astronomical Observatory Skalnaté Pleso. 2020;50(1):203-218
Zakharov Alexander F., Jovanović Predrag, Borka Duško, Borka Jovanović Vesna, "Observational tests of general relativity and alternative theories of gravity with Galactic Center observations using current and future large observational facilities" Contributions of the Astronomical Observatory Skalnaté Pleso, 50, no. 1 (2020):203-218,
https://doi.org/10.31577/caosp.2020.50.1.203 .

Possible observational signatures of supermassive black hole binaries in their Fe Kα line profiles

Jovanović, Predrag; Borka Jovanović, Vesna; Borka, Duško; Popović, Luka Č.

(2020)

TY  - JOUR
AU  - Jovanović, Predrag
AU  - Borka Jovanović, Vesna
AU  - Borka, Duško
AU  - Popović, Luka Č.
PY  - 2020
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/8827
AB  - Here we study the potential observational signatures of supermassive black hole binaries (SMBHBs) in the Fe Kα line profiles emitted from the accretion disks around their components. We simulated the Fe Kα line emission from the relativistic accretion disks using ray tracing method in Kerr metric. The obtained profiles from the SMBHBs are then compared with those in the case of the single supermassive black holes (SMBHs). We considered two models of the SMBHBs: a model when the secondary SMBH is embedded in the accretion disk around the primary, causing an empty gap in the disk, and a model with clearly separated components, where the accretion disks around both primary and secondary give a significant contribution to the composite Fe Kα line emission of a such SMBHB. The obtained results showed that both models of SMBHBs can leave imprints in the form of ripples in the cores of the emitted Fe Kα line profiles, which may look like an absorption component in the line profile. However, in the case of the composite line profiles emitted from two accretion disks, these ripples could have much higher amplitudes and strongly depend on orbital phase of the system, while for those emitted from a disk with an empty gap, the corresponding ripples mostly have lower amplitudes and do not vary significantly with orbital phase. The present day X-ray telescopes are not able to detect such signatures in the observed X-ray spectra of SMBHBs. However this will be possible with the next generation of X-ray observatories, which will also enable application of such effects as a tool for studying the properties of these objects. © 2020, Astronomical Institute, Slovak Academy of Sciences.
T2  - Contributions of the Astronomical Observatory Skalnaté Pleso
T1  - Possible observational signatures of supermassive black hole binaries in their Fe Kα line profiles
VL  - 50
IS  - 1
SP  - 219
EP  - 234
DO  - 10.31577/caosp.2020.50.1.219
ER  - 
@article{
author = "Jovanović, Predrag and Borka Jovanović, Vesna and Borka, Duško and Popović, Luka Č.",
year = "2020",
url = "https://vinar.vin.bg.ac.rs/handle/123456789/8827",
abstract = "Here we study the potential observational signatures of supermassive black hole binaries (SMBHBs) in the Fe Kα line profiles emitted from the accretion disks around their components. We simulated the Fe Kα line emission from the relativistic accretion disks using ray tracing method in Kerr metric. The obtained profiles from the SMBHBs are then compared with those in the case of the single supermassive black holes (SMBHs). We considered two models of the SMBHBs: a model when the secondary SMBH is embedded in the accretion disk around the primary, causing an empty gap in the disk, and a model with clearly separated components, where the accretion disks around both primary and secondary give a significant contribution to the composite Fe Kα line emission of a such SMBHB. The obtained results showed that both models of SMBHBs can leave imprints in the form of ripples in the cores of the emitted Fe Kα line profiles, which may look like an absorption component in the line profile. However, in the case of the composite line profiles emitted from two accretion disks, these ripples could have much higher amplitudes and strongly depend on orbital phase of the system, while for those emitted from a disk with an empty gap, the corresponding ripples mostly have lower amplitudes and do not vary significantly with orbital phase. The present day X-ray telescopes are not able to detect such signatures in the observed X-ray spectra of SMBHBs. However this will be possible with the next generation of X-ray observatories, which will also enable application of such effects as a tool for studying the properties of these objects. © 2020, Astronomical Institute, Slovak Academy of Sciences.",
journal = "Contributions of the Astronomical Observatory Skalnaté Pleso",
title = "Possible observational signatures of supermassive black hole binaries in their Fe Kα line profiles",
volume = "50",
number = "1",
pages = "219-234",
doi = "10.31577/caosp.2020.50.1.219"
}
Jovanović, P., Borka Jovanović, V., Borka, D.,& Popović, L. Č. (2020). Possible observational signatures of supermassive black hole binaries in their Fe Kα line profiles.
Contributions of the Astronomical Observatory Skalnaté Pleso, 50(1), 219-234.
https://doi.org/10.31577/caosp.2020.50.1.219
Jovanović P, Borka Jovanović V, Borka D, Popović LČ. Possible observational signatures of supermassive black hole binaries in their Fe Kα line profiles. Contributions of the Astronomical Observatory Skalnaté Pleso. 2020;50(1):219-234
Jovanović Predrag, Borka Jovanović Vesna, Borka Duško, Popović Luka Č., "Possible observational signatures of supermassive black hole binaries in their Fe Kα line profiles" Contributions of the Astronomical Observatory Skalnaté Pleso, 50, no. 1 (2020):219-234,
https://doi.org/10.31577/caosp.2020.50.1.219 .
8
1

Constraining nonlocal gravity by S2 star orbits

Dialektopoulos, Konstantinos F.; Borka, Duško; Capozziello, Salvatore; Borka Jovanović, Vesna; Jovanović, Predrag

(2019)

TY  - JOUR
AU  - Dialektopoulos, Konstantinos F.
AU  - Borka, Duško
AU  - Capozziello, Salvatore
AU  - Borka Jovanović, Vesna
AU  - Jovanović, Predrag
PY  - 2019
UR  - https://link.aps.org/doi/10.1103/PhysRevD.99.044053
UR  - http://vinar.vin.bg.ac.rs/handle/123456789/8084
AB  - Nonlocal theories of gravity have recently drawn a lot of attention because they can suitably represent the behavior of gravitational interaction in the ultraviolet regime. Furthermore, at infrared scales, they give rise to notable cosmological effects which could be important to describe the dark energy behavior. In particular, exponential forms of the distortion function seem particularly useful for this purpose. Using Noether symmetries, it can be shown that the only nontrivial form of the distortion function is the exponential one, which is working not only for cosmological minisuperspaces, but also in a spherically symmetric spacetime. Taking this result into account, we study the weak-field approximation of this type of nonlocal gravity, and comparing with the orbits of the S2 star around the Galactic center (NTT/VLT data), we set constraints on the parameters of the theory. Nonlocal effects do not play a significant role on the orbits of S2 stars around Sgr A∗ but give richer phenomenology at cosmological scales than the ΛCDM model. Also, we show that the nonlocal gravity model gives better agreement between theory and astronomical observations than Keplerian orbits. © 2019 American Physical Society.
T2  - Physical Review D
T1  - Constraining nonlocal gravity by S2 star orbits
VL  - 99
IS  - 4
SP  - 044053
DO  - 10.1103/PhysRevD.99.044053
ER  - 
@article{
author = "Dialektopoulos, Konstantinos F. and Borka, Duško and Capozziello, Salvatore and Borka Jovanović, Vesna and Jovanović, Predrag",
year = "2019",
url = "https://link.aps.org/doi/10.1103/PhysRevD.99.044053, http://vinar.vin.bg.ac.rs/handle/123456789/8084",
abstract = "Nonlocal theories of gravity have recently drawn a lot of attention because they can suitably represent the behavior of gravitational interaction in the ultraviolet regime. Furthermore, at infrared scales, they give rise to notable cosmological effects which could be important to describe the dark energy behavior. In particular, exponential forms of the distortion function seem particularly useful for this purpose. Using Noether symmetries, it can be shown that the only nontrivial form of the distortion function is the exponential one, which is working not only for cosmological minisuperspaces, but also in a spherically symmetric spacetime. Taking this result into account, we study the weak-field approximation of this type of nonlocal gravity, and comparing with the orbits of the S2 star around the Galactic center (NTT/VLT data), we set constraints on the parameters of the theory. Nonlocal effects do not play a significant role on the orbits of S2 stars around Sgr A∗ but give richer phenomenology at cosmological scales than the ΛCDM model. Also, we show that the nonlocal gravity model gives better agreement between theory and astronomical observations than Keplerian orbits. © 2019 American Physical Society.",
journal = "Physical Review D",
title = "Constraining nonlocal gravity by S2 star orbits",
volume = "99",
number = "4",
pages = "044053",
doi = "10.1103/PhysRevD.99.044053"
}
Dialektopoulos, K. F., Borka, D., Capozziello, S., Borka Jovanović, V.,& Jovanović, P. (2019). Constraining nonlocal gravity by S2 star orbits.
Physical Review D, 99(4), 044053.
https://doi.org/10.1103/PhysRevD.99.044053
Dialektopoulos KF, Borka D, Capozziello S, Borka Jovanović V, Jovanović P. Constraining nonlocal gravity by S2 star orbits. Physical Review D. 2019;99(4):044053
Dialektopoulos Konstantinos F., Borka Duško, Capozziello Salvatore, Borka Jovanović Vesna, Jovanović Predrag, "Constraining nonlocal gravity by S2 star orbits" Physical Review D, 99, no. 4 (2019):044053,
https://doi.org/10.1103/PhysRevD.99.044053 .
8
5
5
6

Constraining nonlocal gravity by S2 star orbits

Dialektopoulos, Konstantinos F.; Borka, Duško; Capozziello, Salvatore; Borka Jovanović, Vesna; Jovanović, Predrag

(2019)

TY  - JOUR
AU  - Dialektopoulos, Konstantinos F.
AU  - Borka, Duško
AU  - Capozziello, Salvatore
AU  - Borka Jovanović, Vesna
AU  - Jovanović, Predrag
PY  - 2019
UR  - https://link.aps.org/doi/10.1103/PhysRevD.99.044053
UR  - http://vinar.vin.bg.ac.rs/handle/123456789/8090
AB  - Nonlocal theories of gravity have recently drawn a lot of attention because they can suitably represent the behavior of gravitational interaction in the ultraviolet regime. Furthermore, at infrared scales, they give rise to notable cosmological effects which could be important to describe the dark energy behavior. In particular, exponential forms of the distortion function seem particularly useful for this purpose. Using Noether symmetries, it can be shown that the only nontrivial form of the distortion function is the exponential one, which is working not only for cosmological minisuperspaces, but also in a spherically symmetric spacetime. Taking this result into account, we study the weak-field approximation of this type of nonlocal gravity, and comparing with the orbits of the S2 star around the Galactic center (NTT/VLT data), we set constraints on the parameters of the theory. Nonlocal effects do not play a significant role on the orbits of S2 stars around Sgr A∗ but give richer phenomenology at cosmological scales than the ΛCDM model. Also, we show that the nonlocal gravity model gives better agreement between theory and astronomical observations than Keplerian orbits.
T2  - Physical Review D
T1  - Constraining nonlocal gravity by S2 star orbits
VL  - 99
IS  - 4
SP  - 044053
DO  - 10.1103/PhysRevD.99.044053
ER  - 
@article{
author = "Dialektopoulos, Konstantinos F. and Borka, Duško and Capozziello, Salvatore and Borka Jovanović, Vesna and Jovanović, Predrag",
year = "2019",
url = "https://link.aps.org/doi/10.1103/PhysRevD.99.044053, http://vinar.vin.bg.ac.rs/handle/123456789/8090",
abstract = "Nonlocal theories of gravity have recently drawn a lot of attention because they can suitably represent the behavior of gravitational interaction in the ultraviolet regime. Furthermore, at infrared scales, they give rise to notable cosmological effects which could be important to describe the dark energy behavior. In particular, exponential forms of the distortion function seem particularly useful for this purpose. Using Noether symmetries, it can be shown that the only nontrivial form of the distortion function is the exponential one, which is working not only for cosmological minisuperspaces, but also in a spherically symmetric spacetime. Taking this result into account, we study the weak-field approximation of this type of nonlocal gravity, and comparing with the orbits of the S2 star around the Galactic center (NTT/VLT data), we set constraints on the parameters of the theory. Nonlocal effects do not play a significant role on the orbits of S2 stars around Sgr A∗ but give richer phenomenology at cosmological scales than the ΛCDM model. Also, we show that the nonlocal gravity model gives better agreement between theory and astronomical observations than Keplerian orbits.",
journal = "Physical Review D",
title = "Constraining nonlocal gravity by S2 star orbits",
volume = "99",
number = "4",
pages = "044053",
doi = "10.1103/PhysRevD.99.044053"
}
Dialektopoulos, K. F., Borka, D., Capozziello, S., Borka Jovanović, V.,& Jovanović, P. (2019). Constraining nonlocal gravity by S2 star orbits.
Physical Review D, 99(4), 044053.
https://doi.org/10.1103/PhysRevD.99.044053
Dialektopoulos KF, Borka D, Capozziello S, Borka Jovanović V, Jovanović P. Constraining nonlocal gravity by S2 star orbits. Physical Review D. 2019;99(4):044053
Dialektopoulos Konstantinos F., Borka Duško, Capozziello Salvatore, Borka Jovanović Vesna, Jovanović Predrag, "Constraining nonlocal gravity by S2 star orbits" Physical Review D, 99, no. 4 (2019):044053,
https://doi.org/10.1103/PhysRevD.99.044053 .
8
5
5
7

Hyperfine interactions of constituent quarks and the mass spectrum of tetraquark states

Ignjatović, Siniša R.; Borka Jovanović, Vesna; Borka, Duško; Jovanović, Predrag

(2019)

TY  - CONF
AU  - Ignjatović, Siniša R.
AU  - Borka Jovanović, Vesna
AU  - Borka, Duško
AU  - Jovanović, Predrag
PY  - 2019
UR  - http://aip.scitation.org/doi/abs/10.1063/1.5091205
UR  - http://vinar.vin.bg.ac.rs/handle/123456789/8093
AB  - The simplest form of the Hyperfine Interaction (HFI) of quarks is a color-spin interaction, sometimes called Fermi-Breit (FB) HFI. For conventional hadrons, this HFI for quark-antiquark (qq) pairs is twice as strong as the same HFI for quark-quark (qq or qq) pairs, but this difference is absorbed into the different HFI constants for mesons and baryons, which are free parameters of the fits. For tetraquarks, however, qqHFI is only half as strong as the qq/qqHFI and both kinds of pairs coexist within the same state. Hence it is worth investigating a model with different fit constants for qq and qq/q pairs. We have investigated 3 models of spin-color HFI for light scalar tetraquarks: 2 models with single constants for both kinds of pairs and one model with different fit constants. The light scalar nonet is chosen because of a lack of other experimentally observed multiplets interpretable as pure exotic states. Since even the nonet contains only 3 particles with distinct masses (i. e. 3 fit points), the constituent quark masses had to be taken from conventional hadron fits obtained in our previous work. The two-constant model did not prove to be a viable alternative to the one-constant models. © 2019 Author(s).
C3  - AIP Conference Proceedings
T1  - Hyperfine interactions of constituent quarks and the mass spectrum of tetraquark states
VL  - 2075
SP  - 080004
DO  - 10.1063/1.5091205
ER  - 
@conference{
author = "Ignjatović, Siniša R. and Borka Jovanović, Vesna and Borka, Duško and Jovanović, Predrag",
year = "2019",
url = "http://aip.scitation.org/doi/abs/10.1063/1.5091205, http://vinar.vin.bg.ac.rs/handle/123456789/8093",
abstract = "The simplest form of the Hyperfine Interaction (HFI) of quarks is a color-spin interaction, sometimes called Fermi-Breit (FB) HFI. For conventional hadrons, this HFI for quark-antiquark (qq) pairs is twice as strong as the same HFI for quark-quark (qq or qq) pairs, but this difference is absorbed into the different HFI constants for mesons and baryons, which are free parameters of the fits. For tetraquarks, however, qqHFI is only half as strong as the qq/qqHFI and both kinds of pairs coexist within the same state. Hence it is worth investigating a model with different fit constants for qq and qq/q pairs. We have investigated 3 models of spin-color HFI for light scalar tetraquarks: 2 models with single constants for both kinds of pairs and one model with different fit constants. The light scalar nonet is chosen because of a lack of other experimentally observed multiplets interpretable as pure exotic states. Since even the nonet contains only 3 particles with distinct masses (i. e. 3 fit points), the constituent quark masses had to be taken from conventional hadron fits obtained in our previous work. The two-constant model did not prove to be a viable alternative to the one-constant models. © 2019 Author(s).",
journal = "AIP Conference Proceedings",
title = "Hyperfine interactions of constituent quarks and the mass spectrum of tetraquark states",
volume = "2075",
pages = "080004",
doi = "10.1063/1.5091205"
}
Ignjatović, S. R., Borka Jovanović, V., Borka, D.,& Jovanović, P. (2019). Hyperfine interactions of constituent quarks and the mass spectrum of tetraquark states.
AIP Conference Proceedings, 2075, 080004.
https://doi.org/10.1063/1.5091205
Ignjatović SR, Borka Jovanović V, Borka D, Jovanović P. Hyperfine interactions of constituent quarks and the mass spectrum of tetraquark states. AIP Conference Proceedings. 2019;2075:080004
Ignjatović Siniša R., Borka Jovanović Vesna, Borka Duško, Jovanović Predrag, "Hyperfine interactions of constituent quarks and the mass spectrum of tetraquark states" AIP Conference Proceedings, 2075 (2019):080004,
https://doi.org/10.1063/1.5091205 .

Constraining Yukawa gravity from planetary motion in the solar system

Jovanović, Predrag; Borka, Duško; Borka Jovanović, Vesna

(2019)

TY  - JOUR
AU  - Jovanović, Predrag
AU  - Borka, Duško
AU  - Borka Jovanović, Vesna
PY  - 2019
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/8788
AB  - In this work we used the observed additional perihelion precession in the Solar System, obtained from the observations of planets and spacecrafts, to study the possible existence of Yukawa correction term to the Newtonian gravitational potential. Our study was motivated by previous analyses which indicated the possible discrepancies from Newtonian gravity in this form and at wide range of astrophysical scales. Yukawa gravity was introduced to cure some shortcomings of General Relativity (GR) at galactic and extragalactic scales. We demonstrated that this form of gravity can give the values for orbital precession which are comparable or even in better agreement with observations than the corresponding predictions of GR. The obtained results can be used for setting stronger constraints on variation of the gravitational constant G, as well as on the fundamental constant δ of Yukawa gravity. Moreover, Yukawa gravity could be used to improve the results for the motion of planets, other Solar System bodies, as well as spacecrafts, and as a consequence, it can help us to get more reliable predictions for natural hazards in the Solar System, such as potential impacts by near-Earth objects. © 2019, Geographical Institute "Jovan Cviji" of the Serbian Academy of Sciences and Arts. All rights reserved.
T2  - Journal of the Geographical Institute Jovan Cvijic, SASA
T1  - Constraining Yukawa gravity from planetary motion in the solar system
VL  - 69
IS  - 3
SP  - 265
EP  - 269
DO  - 10.2298/IJGI1903265J
ER  - 
@article{
author = "Jovanović, Predrag and Borka, Duško and Borka Jovanović, Vesna",
year = "2019",
url = "https://vinar.vin.bg.ac.rs/handle/123456789/8788",
abstract = "In this work we used the observed additional perihelion precession in the Solar System, obtained from the observations of planets and spacecrafts, to study the possible existence of Yukawa correction term to the Newtonian gravitational potential. Our study was motivated by previous analyses which indicated the possible discrepancies from Newtonian gravity in this form and at wide range of astrophysical scales. Yukawa gravity was introduced to cure some shortcomings of General Relativity (GR) at galactic and extragalactic scales. We demonstrated that this form of gravity can give the values for orbital precession which are comparable or even in better agreement with observations than the corresponding predictions of GR. The obtained results can be used for setting stronger constraints on variation of the gravitational constant G, as well as on the fundamental constant δ of Yukawa gravity. Moreover, Yukawa gravity could be used to improve the results for the motion of planets, other Solar System bodies, as well as spacecrafts, and as a consequence, it can help us to get more reliable predictions for natural hazards in the Solar System, such as potential impacts by near-Earth objects. © 2019, Geographical Institute "Jovan Cviji" of the Serbian Academy of Sciences and Arts. All rights reserved.",
journal = "Journal of the Geographical Institute Jovan Cvijic, SASA",
title = "Constraining Yukawa gravity from planetary motion in the solar system",
volume = "69",
number = "3",
pages = "265-269",
doi = "10.2298/IJGI1903265J"
}
Jovanović, P., Borka, D.,& Borka Jovanović, V. (2019). Constraining Yukawa gravity from planetary motion in the solar system.
Journal of the Geographical Institute Jovan Cvijic, SASA, 69(3), 265-269.
https://doi.org/10.2298/IJGI1903265J
Jovanović P, Borka D, Borka Jovanović V. Constraining Yukawa gravity from planetary motion in the solar system. Journal of the Geographical Institute Jovan Cvijic, SASA. 2019;69(3):265-269
Jovanović Predrag, Borka Duško, Borka Jovanović Vesna, "Constraining Yukawa gravity from planetary motion in the solar system" Journal of the Geographical Institute Jovan Cvijic, SASA, 69, no. 3 (2019):265-269,
https://doi.org/10.2298/IJGI1903265J .

Angular and spatial distributions of protons channeled in a bent and radially deformed single-wall boron-nitride nanotubes

Borka, Duško; Galijaš, Sava M. D.

(2019)

TY  - JOUR
AU  - Borka, Duško
AU  - Galijaš, Sava M. D.
PY  - 2019
UR  - http://vinar.vin.bg.ac.rs/handle/123456789/8502
AB  - This study is devoted to the angular and spatial distribution of protons channeling through a bent and radially deformed single-wall boron-nitride nanotubes (SWBNNTs). These nanotubes are more thermal and chemical stable then carbon nanotubes, and they are good candidates for future channeling experiments. This investigation is continuation of our previous study [1, 2] and now we investigate channeling properties of SWBNNTs as a function of the very realistic effects: bending angle of nanotube and its radial deformation. For the first time we presented here investigation of these effects with boron-nitride nanotubes and combination of both effect. The angular and spatial distributions of channeled protons were generated using the Molière’s expression for the continuum potential of the SWBNNT’s atoms and computer simulation method. We also calculate the total yield of protons channeled in the nanotubes as a function of the bending angle. We demonstrate that varying bending angle and taking into account radial deformation we can get a significant rearrangement of the propagating protons within the boron-nitride nanotube. This investigation may be very useful to give us detailed information on the relevant interaction potentials inside SWBNNTs and for creating nanosized proton beams to be used in different applications in medicine and materials science. © 2019, Editura Academiei Romane. All rights reserved.
T2  - Romanian Reports in Physics
T1  - Angular and spatial distributions of protons channeled in a bent and radially deformed single-wall boron-nitride nanotubes
VL  - 71
IS  - 3
SP  - 207
ER  - 
@article{
author = "Borka, Duško and Galijaš, Sava M. D.",
year = "2019",
url = "http://vinar.vin.bg.ac.rs/handle/123456789/8502",
abstract = "This study is devoted to the angular and spatial distribution of protons channeling through a bent and radially deformed single-wall boron-nitride nanotubes (SWBNNTs). These nanotubes are more thermal and chemical stable then carbon nanotubes, and they are good candidates for future channeling experiments. This investigation is continuation of our previous study [1, 2] and now we investigate channeling properties of SWBNNTs as a function of the very realistic effects: bending angle of nanotube and its radial deformation. For the first time we presented here investigation of these effects with boron-nitride nanotubes and combination of both effect. The angular and spatial distributions of channeled protons were generated using the Molière’s expression for the continuum potential of the SWBNNT’s atoms and computer simulation method. We also calculate the total yield of protons channeled in the nanotubes as a function of the bending angle. We demonstrate that varying bending angle and taking into account radial deformation we can get a significant rearrangement of the propagating protons within the boron-nitride nanotube. This investigation may be very useful to give us detailed information on the relevant interaction potentials inside SWBNNTs and for creating nanosized proton beams to be used in different applications in medicine and materials science. © 2019, Editura Academiei Romane. All rights reserved.",
journal = "Romanian Reports in Physics",
title = "Angular and spatial distributions of protons channeled in a bent and radially deformed single-wall boron-nitride nanotubes",
volume = "71",
number = "3",
pages = "207"
}
Borka, D.,& Galijaš, S. M. D. (2019). Angular and spatial distributions of protons channeled in a bent and radially deformed single-wall boron-nitride nanotubes.
Romanian Reports in Physics, 71(3), 207.
Borka D, Galijaš SMD. Angular and spatial distributions of protons channeled in a bent and radially deformed single-wall boron-nitride nanotubes. Romanian Reports in Physics. 2019;71(3):207
Borka Duško, Galijaš Sava M. D., "Angular and spatial distributions of protons channeled in a bent and radially deformed single-wall boron-nitride nanotubes" Romanian Reports in Physics, 71, no. 3 (2019):207
1

Constraining the range of Yukawa gravity interaction from S2 star orbits III: improvement expectations for graviton mass bounds

Zakharov, Alexander F.; Jovanović, Predrag; Borka, Duško; Borka Jovanović, Vesna

(2018)

TY  - JOUR
AU  - Zakharov, Alexander F.
AU  - Jovanović, Predrag
AU  - Borka, Duško
AU  - Borka Jovanović, Vesna
PY  - 2018
UR  - http://stacks.iop.org/1475-7516/2018/i=04/a=050?key=crossref.a23e3c8d44b40fe0c07114ff29f9d9ae
UR  - http://vinar.vin.bg.ac.rs/handle/123456789/7668
AB  - Recently, the LIGO-Virgo collaboration discovered gravitational waves and in their first publication on the subject the authors also presented a graviton mass constraint as m(g) < 1.2 x 10(-22) eV {[}1] (see also more details in a complimentary paper {[}2]). In our previous papers we considered constraints on Yukawa gravity parameters {[}3] and on graviton mass from analysis of the trajectory of S2 star near the Galactic Center {[}4]. In the paper we analyze a potential to reduce upper bounds for graviton mass with future observational data on trajectories of bright stars near the Galactic Center. Since gravitational potentials are different for these two cases, expressions for relativistic advance for general relativity and Yukawa potential are different functions on eccentricity and semimajor axis, it gives an opportunity to improve current estimates of graviton mass with future observational facilities. In our considerations of an improvement potential for a graviton mass estimate we adopt a conservative strategy and assume that trajectories of bright stars and their apocenter advance will be described with general relativity expressions and it gives opportunities to improve graviton mass constraints. In contrast with our previous studies, where we present current constraints on parameters of Yukawa gravity {[}3] and graviton mass {[}4] from observations of S2 star, in the paper we express expectations to improve current constraints for graviton mass, assuming the GR predictions about apocenter shifts will be confirmed with future observations. We concluded that if future observations of bright star orbits during around fifty years will confirm GR predictions about apocenter shifts of bright star orbits it give an opportunity to constrain a graviton mass at a level around 5 x 10(-23) eV or slightly better than current estimates obtained with LIGO observations.
T2  - Journal of Cosmology and Astroparticle Physics
T1  - Constraining the range of Yukawa gravity interaction from S2 star orbits III: improvement expectations for graviton mass bounds
VL  - 2018
IS  - 04
SP  - 050
EP  - 050
DO  - 10.1088/1475-7516/2018/04/050
ER  - 
@article{
author = "Zakharov, Alexander F. and Jovanović, Predrag and Borka, Duško and Borka Jovanović, Vesna",
year = "2018",
url = "http://stacks.iop.org/1475-7516/2018/i=04/a=050?key=crossref.a23e3c8d44b40fe0c07114ff29f9d9ae, http://vinar.vin.bg.ac.rs/handle/123456789/7668",
abstract = "Recently, the LIGO-Virgo collaboration discovered gravitational waves and in their first publication on the subject the authors also presented a graviton mass constraint as m(g) < 1.2 x 10(-22) eV {[}1] (see also more details in a complimentary paper {[}2]). In our previous papers we considered constraints on Yukawa gravity parameters {[}3] and on graviton mass from analysis of the trajectory of S2 star near the Galactic Center {[}4]. In the paper we analyze a potential to reduce upper bounds for graviton mass with future observational data on trajectories of bright stars near the Galactic Center. Since gravitational potentials are different for these two cases, expressions for relativistic advance for general relativity and Yukawa potential are different functions on eccentricity and semimajor axis, it gives an opportunity to improve current estimates of graviton mass with future observational facilities. In our considerations of an improvement potential for a graviton mass estimate we adopt a conservative strategy and assume that trajectories of bright stars and their apocenter advance will be described with general relativity expressions and it gives opportunities to improve graviton mass constraints. In contrast with our previous studies, where we present current constraints on parameters of Yukawa gravity {[}3] and graviton mass {[}4] from observations of S2 star, in the paper we express expectations to improve current constraints for graviton mass, assuming the GR predictions about apocenter shifts will be confirmed with future observations. We concluded that if future observations of bright star orbits during around fifty years will confirm GR predictions about apocenter shifts of bright star orbits it give an opportunity to constrain a graviton mass at a level around 5 x 10(-23) eV or slightly better than current estimates obtained with LIGO observations.",
journal = "Journal of Cosmology and Astroparticle Physics",
title = "Constraining the range of Yukawa gravity interaction from S2 star orbits III: improvement expectations for graviton mass bounds",
volume = "2018",
number = "04",
pages = "050-050",
doi = "10.1088/1475-7516/2018/04/050"
}
Zakharov, A. F., Jovanović, P., Borka, D.,& Borka Jovanović, V. (2018). Constraining the range of Yukawa gravity interaction from S2 star orbits III: improvement expectations for graviton mass bounds.
Journal of Cosmology and Astroparticle Physics, 2018(04), 050-050.
https://doi.org/10.1088/1475-7516/2018/04/050
Zakharov AF, Jovanović P, Borka D, Borka Jovanović V. Constraining the range of Yukawa gravity interaction from S2 star orbits III: improvement expectations for graviton mass bounds. Journal of Cosmology and Astroparticle Physics. 2018;2018(04):050-050
Zakharov Alexander F., Jovanović Predrag, Borka Duško, Borka Jovanović Vesna, "Constraining the range of Yukawa gravity interaction from S2 star orbits III: improvement expectations for graviton mass bounds" Journal of Cosmology and Astroparticle Physics, 2018, no. 04 (2018):050-050,
https://doi.org/10.1088/1475-7516/2018/04/050 .
9
17
17
15

Galactic Structures from Gravitational Radii

Capozziello, Salvatore; Borka, Duško; Borka Jovanović, Vesna; Jovanović, Predrag

(2018)

TY  - CONF
AU  - Capozziello, Salvatore
AU  - Borka, Duško
AU  - Borka Jovanović, Vesna
AU  - Jovanović, Predrag
PY  - 2018
UR  - http://www.mdpi.com/2075-4434/6/1/22
UR  - http://vinar.vin.bg.ac.rs/handle/123456789/7748
AB  - We demonstrate that the existence of a Noether symmetry in f (R) theories of gravity gives rise to an additional gravitational radius, besides the standard Schwarzschild one, determining the dynamics at galactic scales. By this feature, it is possible to explain the baryonic Tully-Fisher relation and the rotation curve of gas-rich galaxies without the dark matter hypothesis. Furthermore, under the same standard, the Fundamental Plane of elliptical galaxies can be addressed.
C3  - Galaxies
T1  - Galactic Structures from Gravitational Radii
VL  - 6
IS  - 1
SP  - 22
DO  - 10.3390/galaxies6010022
ER  - 
@conference{
author = "Capozziello, Salvatore and Borka, Duško and Borka Jovanović, Vesna and Jovanović, Predrag",
year = "2018",
url = "http://www.mdpi.com/2075-4434/6/1/22, http://vinar.vin.bg.ac.rs/handle/123456789/7748",
abstract = "We demonstrate that the existence of a Noether symmetry in f (R) theories of gravity gives rise to an additional gravitational radius, besides the standard Schwarzschild one, determining the dynamics at galactic scales. By this feature, it is possible to explain the baryonic Tully-Fisher relation and the rotation curve of gas-rich galaxies without the dark matter hypothesis. Furthermore, under the same standard, the Fundamental Plane of elliptical galaxies can be addressed.",
journal = "Galaxies",
title = "Galactic Structures from Gravitational Radii",
volume = "6",
number = "1",
pages = "22",
doi = "10.3390/galaxies6010022"
}
Capozziello, S., Borka, D., Borka Jovanović, V.,& Jovanović, P. (2018). Galactic Structures from Gravitational Radii.
Galaxies, 6(1), 22.
https://doi.org/10.3390/galaxies6010022
Capozziello S, Borka D, Borka Jovanović V, Jovanović P. Galactic Structures from Gravitational Radii. Galaxies. 2018;6(1):22
Capozziello Salvatore, Borka Duško, Borka Jovanović Vesna, Jovanović Predrag, "Galactic Structures from Gravitational Radii" Galaxies, 6, no. 1 (2018):22,
https://doi.org/10.3390/galaxies6010022 .
2
2
2
2

Rn gravity as a viable alternative to dark matter: Application to stellar dynamics

Borka Jovanović, Vesna; Jovanović, Predrag; Borka, Duško; Capozziello, Salvatore

(2018)

TY  - JOUR
AU  - Borka Jovanović, Vesna
AU  - Jovanović, Predrag
AU  - Borka, Duško
AU  - Capozziello, Salvatore
PY  - 2018
UR  - https://www.scopus.com/inward/record.uri?eid=2-s2.0-85049593182&partnerID=40&md5=0e3b8f9902a16e5031d0887f554cf214
UR  - http://vinar.vin.bg.ac.rs/handle/123456789/7781
AB  - The role of f(R) gravity, as well as the other modifications of standard Einstein’s gravity, is to explain the accelerated expansion, structure formation of the Universe, and some other phenomena at extragalactic scales (such as e.g. flat rotation curves of spiral galaxies) without adding unknown forms of dark energy or dark matter. In f(R) model, the Ricci scalar in the Einstein–Hilbert action is replaced by a general function of it. Its power-law form Rn is analyzed here using observed orbits of S-stars around the Galactic Center and also their computer simulations. We review the various consequences of the Rn gravity parameters (rc, the characteristic radius, i.e. the scalelength depending on the gravitating system properties; and β, the universal constant) on stellar dynamics and investigate their constraints from the observed S-star orbits. The presented results show that these observations could put reliable constraints on the parameters of Rn gravity.
T2  - Astronomical and Astrophysical Transactions
T1  - Rn gravity as a viable alternative to dark matter: Application to stellar dynamics
VL  - 30
IS  - 3
SP  - 351
EP  - 358
ER  - 
@article{
author = "Borka Jovanović, Vesna and Jovanović, Predrag and Borka, Duško and Capozziello, Salvatore",
year = "2018",
url = "https://www.scopus.com/inward/record.uri?eid=2-s2.0-85049593182&partnerID=40&md5=0e3b8f9902a16e5031d0887f554cf214, http://vinar.vin.bg.ac.rs/handle/123456789/7781",
abstract = "The role of f(R) gravity, as well as the other modifications of standard Einstein’s gravity, is to explain the accelerated expansion, structure formation of the Universe, and some other phenomena at extragalactic scales (such as e.g. flat rotation curves of spiral galaxies) without adding unknown forms of dark energy or dark matter. In f(R) model, the Ricci scalar in the Einstein–Hilbert action is replaced by a general function of it. Its power-law form Rn is analyzed here using observed orbits of S-stars around the Galactic Center and also their computer simulations. We review the various consequences of the Rn gravity parameters (rc, the characteristic radius, i.e. the scalelength depending on the gravitating system properties; and β, the universal constant) on stellar dynamics and investigate their constraints from the observed S-star orbits. The presented results show that these observations could put reliable constraints on the parameters of Rn gravity.",
journal = "Astronomical and Astrophysical Transactions",
title = "Rn gravity as a viable alternative to dark matter: Application to stellar dynamics",
volume = "30",
number = "3",
pages = "351-358"
}
Borka Jovanović, V., Jovanović, P., Borka, D.,& Capozziello, S. (2018). Rn gravity as a viable alternative to dark matter: Application to stellar dynamics.
Astronomical and Astrophysical Transactions, 30(3), 351-358.
Borka Jovanović V, Jovanović P, Borka D, Capozziello S. Rn gravity as a viable alternative to dark matter: Application to stellar dynamics. Astronomical and Astrophysical Transactions. 2018;30(3):351-358
Borka Jovanović Vesna, Jovanović Predrag, Borka Duško, Capozziello Salvatore, "Rn gravity as a viable alternative to dark matter: Application to stellar dynamics" Astronomical and Astrophysical Transactions, 30, no. 3 (2018):351-358

Fundamental Plane of Elliptical Galaxies in f(R) Gravity: The Role of Luminosity

Borka Jovanović, Vesna; Jovanović, Predrag; Borka, Duško; Capozziello, Salvatore

(2018)

TY  - JOUR
AU  - Borka Jovanović, Vesna
AU  - Jovanović, Predrag
AU  - Borka, Duško
AU  - Capozziello, Salvatore
PY  - 2018
UR  - http://www.mdpi.com/2218-2004/7/1/4
UR  - http://vinar.vin.bg.ac.rs/handle/123456789/8218
AB  - The global properties of elliptical galaxies are connected through the so-called fundamental plane of ellipticals, which is an empirical relation between their parameters: effective radius, central velocity dispersion and mean surface brightness within the effective radius. We investigated the relation between the parameters of the fundamental plane equation and the parameters of modified gravity potential f ( R ) . With that aim, we compared theoretical predictions for circular velocity in f ( R ) gravity with the corresponding values from a large sample of observed elliptical galaxies. Besides, we consistently reproduced the values of coefficients of the fundamental plane equation as deduced from observations, showing that the photometric quantities like mean surface brightness are related to gravitational parameters. We show that this type of modified gravity, especially its power-law version— R n , is able to reproduce the stellar dynamics in elliptical galaxies. In addition, it is shown that R n gravity fits the observations very well, without the need for a dark matter.
T2  - Atoms
T1  - Fundamental Plane of Elliptical Galaxies in f(R) Gravity: The Role of Luminosity
VL  - 7
IS  - 1
SP  - 4
DO  - 10.3390/atoms7010004
ER  - 
@article{
author = "Borka Jovanović, Vesna and Jovanović, Predrag and Borka, Duško and Capozziello, Salvatore",
year = "2018",
url = "http://www.mdpi.com/2218-2004/7/1/4, http://vinar.vin.bg.ac.rs/handle/123456789/8218",
abstract = "The global properties of elliptical galaxies are connected through the so-called fundamental plane of ellipticals, which is an empirical relation between their parameters: effective radius, central velocity dispersion and mean surface brightness within the effective radius. We investigated the relation between the parameters of the fundamental plane equation and the parameters of modified gravity potential f ( R ) . With that aim, we compared theoretical predictions for circular velocity in f ( R ) gravity with the corresponding values from a large sample of observed elliptical galaxies. Besides, we consistently reproduced the values of coefficients of the fundamental plane equation as deduced from observations, showing that the photometric quantities like mean surface brightness are related to gravitational parameters. We show that this type of modified gravity, especially its power-law version— R n , is able to reproduce the stellar dynamics in elliptical galaxies. In addition, it is shown that R n gravity fits the observations very well, without the need for a dark matter.",
journal = "Atoms",
title = "Fundamental Plane of Elliptical Galaxies in f(R) Gravity: The Role of Luminosity",
volume = "7",
number = "1",
pages = "4",
doi = "10.3390/atoms7010004"
}
Borka Jovanović, V., Jovanović, P., Borka, D.,& Capozziello, S. (2018). Fundamental Plane of Elliptical Galaxies in f(R) Gravity: The Role of Luminosity.
Atoms, 7(1), 4.
https://doi.org/10.3390/atoms7010004
Borka Jovanović V, Jovanović P, Borka D, Capozziello S. Fundamental Plane of Elliptical Galaxies in f(R) Gravity: The Role of Luminosity. Atoms. 2018;7(1):4
Borka Jovanović Vesna, Jovanović Predrag, Borka Duško, Capozziello Salvatore, "Fundamental Plane of Elliptical Galaxies in f(R) Gravity: The Role of Luminosity" Atoms, 7, no. 1 (2018):4,
https://doi.org/10.3390/atoms7010004 .
8
3
2
2

Backscattered electron spectra from graphite

Borka, Duško; Toth, Jozsef; Tokesi, Karoly

(2018)

TY  - JOUR
AU  - Borka, Duško
AU  - Toth, Jozsef
AU  - Tokesi, Karoly
PY  - 2018
UR  - https://linkinghub.elsevier.com/retrieve/pii/S0375960118307278
UR  - http://vinar.vin.bg.ac.rs/handle/123456789/7794
AB  - The backscattered electron spectra from graphite sample were studied both experimentally and theoretically at impact energies between 500 and 5000 eV. The angle of the incident electron beam was 50° and the detection angle was 0° with respect to the surface normal, respectively. Monte Carlo (MC) simulations were performed based on the Classical Transport Theory (CTT) model to mimic the experimental spectra. In our simulations, both elastic and inelastic scattering of primary electrons and secondary electron emission from graphite are taken into account. There is found satisfactory agreement between measured and calculated electron spectra. © 2018 Elsevier B.V.
T2  - Physics Letters A
T1  - Backscattered electron spectra from graphite
VL  - 382
IS  - 35
SP  - 2470
EP  - 2474
DO  - 10.1016/j.physleta.2018.07.004
ER  - 
@article{
author = "Borka, Duško and Toth, Jozsef and Tokesi, Karoly",
year = "2018",
url = "https://linkinghub.elsevier.com/retrieve/pii/S0375960118307278, http://vinar.vin.bg.ac.rs/handle/123456789/7794",
abstract = "The backscattered electron spectra from graphite sample were studied both experimentally and theoretically at impact energies between 500 and 5000 eV. The angle of the incident electron beam was 50° and the detection angle was 0° with respect to the surface normal, respectively. Monte Carlo (MC) simulations were performed based on the Classical Transport Theory (CTT) model to mimic the experimental spectra. In our simulations, both elastic and inelastic scattering of primary electrons and secondary electron emission from graphite are taken into account. There is found satisfactory agreement between measured and calculated electron spectra. © 2018 Elsevier B.V.",
journal = "Physics Letters A",
title = "Backscattered electron spectra from graphite",
volume = "382",
number = "35",
pages = "2470-2474",
doi = "10.1016/j.physleta.2018.07.004"
}
Borka, D., Toth, J.,& Tokesi, K. (2018). Backscattered electron spectra from graphite.
Physics Letters A, 382(35), 2470-2474.
https://doi.org/10.1016/j.physleta.2018.07.004
Borka D, Toth J, Tokesi K. Backscattered electron spectra from graphite. Physics Letters A. 2018;382(35):2470-2474
Borka Duško, Toth Jozsef, Tokesi Karoly, "Backscattered electron spectra from graphite" Physics Letters A, 382, no. 35 (2018):2470-2474,
https://doi.org/10.1016/j.physleta.2018.07.004 .
1
2
1
2

Analytical modeling of electron energy loss spectroscopy of graphene: Ab initio study versus extended hydrodynamic model

Đorđević, Tijana; Radović, Ivan; Despoja, Vito; Lyon, Keenan; Borka, Duško; Miskovic, Zoran L.

(2018)

TY  - JOUR
AU  - Đorđević, Tijana
AU  - Radović, Ivan
AU  - Despoja, Vito
AU  - Lyon, Keenan
AU  - Borka, Duško
AU  - Miskovic, Zoran L.
PY  - 2018
UR  - http://vinar.vin.bg.ac.rs/handle/123456789/1831
AB  - We present an analytical modeling of the electron energy loss (EEL) spectroscopy data for free-standing graphene obtained by scanning transmission electron microscope. The probability density for energy loss of fast electrons traversing graphene under normal incidence is evaluated using an optical approximation based on the conductivity of graphene given in the local, i.e., frequency-dependent form derived by both a two-dimensional, two-fluid extended hydrodynamic (eHD) model and an ab initio method. We compare the results for the real and imaginary parts of the optical conductivity in graphene obtained by these two methods. The calculated probability density is directly compared with the EEL spectra from three independent experiments and we find very good agreement, especially in the case of the eHD model. Furthermore, we point out that the subtraction of the zero-loss peak from the experimental EEL spectra has a strong influence on the analytical model for the EEL spectroscopy data. (C) 2017 Elsevier B.V. All rights reserved.
T2  - Ultramicroscopy
T1  - Analytical modeling of electron energy loss spectroscopy of graphene: Ab initio study versus extended hydrodynamic model
VL  - 184
SP  - 134
EP  - 142
DO  - 10.1016/j.ultramic.2017.08.014
ER  - 
@article{
author = "Đorđević, Tijana and Radović, Ivan and Despoja, Vito and Lyon, Keenan and Borka, Duško and Miskovic, Zoran L.",
year = "2018",
url = "http://vinar.vin.bg.ac.rs/handle/123456789/1831",
abstract = "We present an analytical modeling of the electron energy loss (EEL) spectroscopy data for free-standing graphene obtained by scanning transmission electron microscope. The probability density for energy loss of fast electrons traversing graphene under normal incidence is evaluated using an optical approximation based on the conductivity of graphene given in the local, i.e., frequency-dependent form derived by both a two-dimensional, two-fluid extended hydrodynamic (eHD) model and an ab initio method. We compare the results for the real and imaginary parts of the optical conductivity in graphene obtained by these two methods. The calculated probability density is directly compared with the EEL spectra from three independent experiments and we find very good agreement, especially in the case of the eHD model. Furthermore, we point out that the subtraction of the zero-loss peak from the experimental EEL spectra has a strong influence on the analytical model for the EEL spectroscopy data. (C) 2017 Elsevier B.V. All rights reserved.",
journal = "Ultramicroscopy",
title = "Analytical modeling of electron energy loss spectroscopy of graphene: Ab initio study versus extended hydrodynamic model",
volume = "184",
pages = "134-142",
doi = "10.1016/j.ultramic.2017.08.014"
}
Đorđević, T., Radović, I., Despoja, V., Lyon, K., Borka, D.,& Miskovic, Z. L. (2018). Analytical modeling of electron energy loss spectroscopy of graphene: Ab initio study versus extended hydrodynamic model.
Ultramicroscopy, 184, 134-142.
https://doi.org/10.1016/j.ultramic.2017.08.014
Đorđević T, Radović I, Despoja V, Lyon K, Borka D, Miskovic ZL. Analytical modeling of electron energy loss spectroscopy of graphene: Ab initio study versus extended hydrodynamic model. Ultramicroscopy. 2018;184:134-142
Đorđević Tijana, Radović Ivan, Despoja Vito, Lyon Keenan, Borka Duško, Miskovic Zoran L., "Analytical modeling of electron energy loss spectroscopy of graphene: Ab initio study versus extended hydrodynamic model" Ultramicroscopy, 184 (2018):134-142,
https://doi.org/10.1016/j.ultramic.2017.08.014 .
7
8
8

Electron transmission through a steel capillary

Maljković, Jelena B.; Borka, Duško; Ranković, Miloš Lj.; Marinković, Bratislav P.; Milosavljević, Aleksandar R.; Lemell, Christoph; Tokesi, Karoly

(2018)

TY  - JOUR
AU  - Maljković, Jelena B.
AU  - Borka, Duško
AU  - Ranković, Miloš Lj.
AU  - Marinković, Bratislav P.
AU  - Milosavljević, Aleksandar R.
AU  - Lemell, Christoph
AU  - Tokesi, Karoly
PY  - 2018
UR  - http://linkinghub.elsevier.com/retrieve/pii/S0168583X18301903
UR  - http://vinar.vin.bg.ac.rs/handle/123456789/7656
AB  - The transmission of low-energy electrons through a macroscopic steel capillary has been investigated both experimentally and theoretically. The length of the steel capillary was L = 19.5 mm and the inner diameter was d = 0.9 mm. The kinetic energy distribution of electrons transmitted through the steel capillary was recorded for a tilt angle of psi = 2.6 degrees of the incident electron beam with respect to the capillary axis. Accompanying simulations based on classical transport theory reproduce the experimental data to a high degree of agreement. Transmission for other tilt angles has also been simulated to investigate the influence of the tilt angle on the guiding efficiency.
T2  - Nuclear Instruments and Methods in Physics Research. Section B: Beam Interactions with Materials and Atoms
T1  - Electron transmission through a steel capillary
VL  - 423
SP  - 87
EP  - 91
DO  - 10.1016/j.nimb.2018.03.020
ER  - 
@article{
author = "Maljković, Jelena B. and Borka, Duško and Ranković, Miloš Lj. and Marinković, Bratislav P. and Milosavljević, Aleksandar R. and Lemell, Christoph and Tokesi, Karoly",
year = "2018",
url = "http://linkinghub.elsevier.com/retrieve/pii/S0168583X18301903, http://vinar.vin.bg.ac.rs/handle/123456789/7656",
abstract = "The transmission of low-energy electrons through a macroscopic steel capillary has been investigated both experimentally and theoretically. The length of the steel capillary was L = 19.5 mm and the inner diameter was d = 0.9 mm. The kinetic energy distribution of electrons transmitted through the steel capillary was recorded for a tilt angle of psi = 2.6 degrees of the incident electron beam with respect to the capillary axis. Accompanying simulations based on classical transport theory reproduce the experimental data to a high degree of agreement. Transmission for other tilt angles has also been simulated to investigate the influence of the tilt angle on the guiding efficiency.",
journal = "Nuclear Instruments and Methods in Physics Research. Section B: Beam Interactions with Materials and Atoms",
title = "Electron transmission through a steel capillary",
volume = "423",
pages = "87-91",
doi = "10.1016/j.nimb.2018.03.020"
}
Maljković, J. B., Borka, D., Ranković, M. Lj., Marinković, B. P., Milosavljević, A. R., Lemell, C.,& Tokesi, K. (2018). Electron transmission through a steel capillary.
Nuclear Instruments and Methods in Physics Research. Section B: Beam Interactions with Materials and Atoms, 423, 87-91.
https://doi.org/10.1016/j.nimb.2018.03.020
Maljković JB, Borka D, Ranković ML, Marinković BP, Milosavljević AR, Lemell C, Tokesi K. Electron transmission through a steel capillary. Nuclear Instruments and Methods in Physics Research. Section B: Beam Interactions with Materials and Atoms. 2018;423:87-91
Maljković Jelena B., Borka Duško, Ranković Miloš Lj., Marinković Bratislav P., Milosavljević Aleksandar R., Lemell Christoph, Tokesi Karoly, "Electron transmission through a steel capillary" Nuclear Instruments and Methods in Physics Research. Section B: Beam Interactions with Materials and Atoms, 423 (2018):87-91,
https://doi.org/10.1016/j.nimb.2018.03.020 .
1
1
1

Snr Radio Spectral Index Distribution and Its Correlation with Polarization. a Case Study: the Lupus Loop

Borka Jovanović, Vesna; Jovanović, Predrag; Borka, Duško

(2017)

TY  - JOUR
AU  - Borka Jovanović, Vesna
AU  - Jovanović, Predrag
AU  - Borka, Duško
PY  - 2017
UR  - http://vinar.vin.bg.ac.rs/handle/123456789/1496
AB  - We use radio-continuum all-sky surveys at 1420 and 408 MHz with the aim to investigate properties of the Galactic radio source Lupus Loop. The survey data at 1435 MHz, with the linear polarization of the southern sky, are also used. We calculate properties of this supernova remnant: the brightness temperature, surface brightness and radio spectral index. To determine its borders and to calculate its properties, we use the method we have developed. The non-thermal nature of its radiation is confirmed. The distribution of spectral index over its area is also given. A significant correlation between the radio spectral index distribution and the corresponding polarized intensity distribution inside the loop borders is found, indicating that the polarization maps could provide us information about the distribution of the interstellar medium, and thus could represent one additional way to search for new Galactic loops.
T2  - Revista Mexicana de Astronomia y Astrofisica
T1  - Snr Radio Spectral Index Distribution and Its Correlation with Polarization. a Case Study: the Lupus Loop
VL  - 53
IS  - 1
SP  - 37
EP  - 44
ER  - 
@article{
author = "Borka Jovanović, Vesna and Jovanović, Predrag and Borka, Duško",
year = "2017",
url = "http://vinar.vin.bg.ac.rs/handle/123456789/1496",
abstract = "We use radio-continuum all-sky surveys at 1420 and 408 MHz with the aim to investigate properties of the Galactic radio source Lupus Loop. The survey data at 1435 MHz, with the linear polarization of the southern sky, are also used. We calculate properties of this supernova remnant: the brightness temperature, surface brightness and radio spectral index. To determine its borders and to calculate its properties, we use the method we have developed. The non-thermal nature of its radiation is confirmed. The distribution of spectral index over its area is also given. A significant correlation between the radio spectral index distribution and the corresponding polarized intensity distribution inside the loop borders is found, indicating that the polarization maps could provide us information about the distribution of the interstellar medium, and thus could represent one additional way to search for new Galactic loops.",
journal = "Revista Mexicana de Astronomia y Astrofisica",
title = "Snr Radio Spectral Index Distribution and Its Correlation with Polarization. a Case Study: the Lupus Loop",
volume = "53",
number = "1",
pages = "37-44"
}
Borka Jovanović, V., Jovanović, P.,& Borka, D. (2017). Snr Radio Spectral Index Distribution and Its Correlation with Polarization. a Case Study: the Lupus Loop.
Revista Mexicana de Astronomia y Astrofisica, 53(1), 37-44.
Borka Jovanović V, Jovanović P, Borka D. Snr Radio Spectral Index Distribution and Its Correlation with Polarization. a Case Study: the Lupus Loop. Revista Mexicana de Astronomia y Astrofisica. 2017;53(1):37-44
Borka Jovanović Vesna, Jovanović Predrag, Borka Duško, "Snr Radio Spectral Index Distribution and Its Correlation with Polarization. a Case Study: the Lupus Loop" Revista Mexicana de Astronomia y Astrofisica, 53, no. 1 (2017):37-44

Addressing the missing matter problem in galaxies through a new fundamental gravitational radius

Capozziello, Salvatore; Jovanović, Predrag; Borka Jovanović, Vesna; Borka, Duško

(2017)

TY  - JOUR
AU  - Capozziello, Salvatore
AU  - Jovanović, Predrag
AU  - Borka Jovanović, Vesna
AU  - Borka, Duško
PY  - 2017
UR  - http://vinar.vin.bg.ac.rs/handle/123456789/1696
AB  - We demonstrate that the existence of a Noether symmetry in f theories of gravity gives rise to a further gravitational radius, besides tile standard Schwarzschild one, determining the dynamics at galactic scales. By this feature, it is possible to explain the baryonic Fully-Fisher relation and the rotation curve of gas-rich galaxies without the dark matter hypothesis.
T2  - Journal of Cosmology and Astroparticle Physics
T1  - Addressing the missing matter problem in galaxies through a new fundamental gravitational radius
IS  - 6
DO  - 10.1088/1475-7516/2017/06/044
ER  - 
@article{
author = "Capozziello, Salvatore and Jovanović, Predrag and Borka Jovanović, Vesna and Borka, Duško",
year = "2017",
url = "http://vinar.vin.bg.ac.rs/handle/123456789/1696",
abstract = "We demonstrate that the existence of a Noether symmetry in f theories of gravity gives rise to a further gravitational radius, besides tile standard Schwarzschild one, determining the dynamics at galactic scales. By this feature, it is possible to explain the baryonic Fully-Fisher relation and the rotation curve of gas-rich galaxies without the dark matter hypothesis.",
journal = "Journal of Cosmology and Astroparticle Physics",
title = "Addressing the missing matter problem in galaxies through a new fundamental gravitational radius",
number = "6",
doi = "10.1088/1475-7516/2017/06/044"
}
Capozziello, S., Jovanović, P., Borka Jovanović, V.,& Borka, D. (2017). Addressing the missing matter problem in galaxies through a new fundamental gravitational radius.
Journal of Cosmology and Astroparticle Physics(6).
https://doi.org/10.1088/1475-7516/2017/06/044
Capozziello S, Jovanović P, Borka Jovanović V, Borka D. Addressing the missing matter problem in galaxies through a new fundamental gravitational radius. Journal of Cosmology and Astroparticle Physics. 2017;(6)
Capozziello Salvatore, Jovanović Predrag, Borka Jovanović Vesna, Borka Duško, "Addressing the missing matter problem in galaxies through a new fundamental gravitational radius" Journal of Cosmology and Astroparticle Physics, no. 6 (2017),
https://doi.org/10.1088/1475-7516/2017/06/044 .
2
24
24
23

Graviton mass evaluation with trajectories of bright stars at the Galactic Center

Zakharov, Alexander F.; Jovanović, Predrag; Borka, Duško; Borka Jovanović, Vesna

(2017)

TY  - CONF
AU  - Zakharov, Alexander F.
AU  - Jovanović, Predrag
AU  - Borka, Duško
AU  - Borka Jovanović, Vesna
PY  - 2017
UR  - http://vinar.vin.bg.ac.rs/handle/123456789/7166
AB  - One could use trajectories of test particles to evaluate a gravitational potential. In particular, in the case of the Galactic Center one could use photon trajectories to analyze a shadow structure. Another way is to use bright stars near the Galactic Center to evaluate a gravitational potential and constrain parameters of a model for the Galactic Center. In particular, one could obtain constraints on parameters of black hole, stellar cluster and dark matter concentration. Earlier, we constrained parameters of Fr and a Yukawa potential from observational data for the S2 star trajectory. Now gravity theories with a massive graviton are a subject of intensive studies. People proposed different experimental ways to evaluate a graviton mass. Recently, the joint LIGO and VIRGO collaboration reported not only a discovery of gravitational waves and binary black holes, but the team claimed also that found a constraint on a graviton mass as 1.2 x 10(-22) eV. We show that an analysis of the S2 star trajectory could constrain a graviton mass with a comparable accuracy and this constraint is consistent with LIGOs one.
C3  - Journal of Physics: Conference Series
T1  - Graviton mass evaluation with trajectories of bright stars at the Galactic Center
VL  - 798
DO  - 10.1088/1742-6596/798/1/012081
ER  - 
@conference{
author = "Zakharov, Alexander F. and Jovanović, Predrag and Borka, Duško and Borka Jovanović, Vesna",
year = "2017",
url = "http://vinar.vin.bg.ac.rs/handle/123456789/7166",
abstract = "One could use trajectories of test particles to evaluate a gravitational potential. In particular, in the case of the Galactic Center one could use photon trajectories to analyze a shadow structure. Another way is to use bright stars near the Galactic Center to evaluate a gravitational potential and constrain parameters of a model for the Galactic Center. In particular, one could obtain constraints on parameters of black hole, stellar cluster and dark matter concentration. Earlier, we constrained parameters of Fr and a Yukawa potential from observational data for the S2 star trajectory. Now gravity theories with a massive graviton are a subject of intensive studies. People proposed different experimental ways to evaluate a graviton mass. Recently, the joint LIGO and VIRGO collaboration reported not only a discovery of gravitational waves and binary black holes, but the team claimed also that found a constraint on a graviton mass as 1.2 x 10(-22) eV. We show that an analysis of the S2 star trajectory could constrain a graviton mass with a comparable accuracy and this constraint is consistent with LIGOs one.",
journal = "Journal of Physics: Conference Series",
title = "Graviton mass evaluation with trajectories of bright stars at the Galactic Center",
volume = "798",
doi = "10.1088/1742-6596/798/1/012081"
}
Zakharov, A. F., Jovanović, P., Borka, D.,& Borka Jovanović, V. (2017). Graviton mass evaluation with trajectories of bright stars at the Galactic Center.
Journal of Physics: Conference Series, 798.
https://doi.org/10.1088/1742-6596/798/1/012081
Zakharov AF, Jovanović P, Borka D, Borka Jovanović V. Graviton mass evaluation with trajectories of bright stars at the Galactic Center. Journal of Physics: Conference Series. 2017;798
Zakharov Alexander F., Jovanović Predrag, Borka Duško, Borka Jovanović Vesna, "Graviton mass evaluation with trajectories of bright stars at the Galactic Center" Journal of Physics: Conference Series, 798 (2017),
https://doi.org/10.1088/1742-6596/798/1/012081 .
8
8
9

Graviton mass bounds from an analysis of bright star trajectories at the Galactic Center

Zakharov, Alexander F.; Jovanović, Predrag; Borka, Duško; Borka Jovanović, Vesna

(2017)

TY  - CONF
AU  - Zakharov, Alexander F.
AU  - Jovanović, Predrag
AU  - Borka, Duško
AU  - Borka Jovanović, Vesna
PY  - 2017
UR  - http://vinar.vin.bg.ac.rs/handle/123456789/7172
AB  - In February 2016 the LIGO and VIRGO collaboration reported the discovery of gravitational waves in merging black holes, therefore, the team confirmed GR predictions about an existence of black holes and gravitational waves in the strong gravitational field limit. Moreover, in their papers the joint LIGO and VIRGO team presented an upper limit on graviton mass such as m(g) LT 1.2 x 10(-22) eV (Abbott et al. 2016). So, the authors concluded that their observational data do not show any violation of classical general relativity. We show that an analysis of bright star trajectories could constrain graviton mass with a comparable accuracy with accuracies reached with gravitational wave interferometers and the estimate is consistent with the one obtained by the LIGO and VIRGO collaboration. This analysis gives an opportunity to treat observations of bright stars near the Galactic Center as a useful tool to obtain constraints on the fundamental gravity law such as modifications of the Newton gravity law in a weak field approximation. In that way, based on a potential reconstruction at the Galactic Center we obtain bounds on a graviton mass.
C3  - EPJ Web of Conferences
T1  - Graviton mass bounds from an analysis of bright star trajectories at the Galactic Center
VL  - 138
SP  - UNSP 01010
DO  - 10.1051/epjconf/201713801010
ER  - 
@conference{
author = "Zakharov, Alexander F. and Jovanović, Predrag and Borka, Duško and Borka Jovanović, Vesna",
year = "2017",
url = "http://vinar.vin.bg.ac.rs/handle/123456789/7172",
abstract = "In February 2016 the LIGO and VIRGO collaboration reported the discovery of gravitational waves in merging black holes, therefore, the team confirmed GR predictions about an existence of black holes and gravitational waves in the strong gravitational field limit. Moreover, in their papers the joint LIGO and VIRGO team presented an upper limit on graviton mass such as m(g) LT 1.2 x 10(-22) eV (Abbott et al. 2016). So, the authors concluded that their observational data do not show any violation of classical general relativity. We show that an analysis of bright star trajectories could constrain graviton mass with a comparable accuracy with accuracies reached with gravitational wave interferometers and the estimate is consistent with the one obtained by the LIGO and VIRGO collaboration. This analysis gives an opportunity to treat observations of bright stars near the Galactic Center as a useful tool to obtain constraints on the fundamental gravity law such as modifications of the Newton gravity law in a weak field approximation. In that way, based on a potential reconstruction at the Galactic Center we obtain bounds on a graviton mass.",
journal = "EPJ Web of Conferences",
title = "Graviton mass bounds from an analysis of bright star trajectories at the Galactic Center",
volume = "138",
pages = "UNSP 01010",
doi = "10.1051/epjconf/201713801010"
}
Zakharov, A. F., Jovanović, P., Borka, D.,& Borka Jovanović, V. (2017). Graviton mass bounds from an analysis of bright star trajectories at the Galactic Center.
EPJ Web of Conferences, 138, UNSP 01010.
https://doi.org/10.1051/epjconf/201713801010
Zakharov AF, Jovanović P, Borka D, Borka Jovanović V. Graviton mass bounds from an analysis of bright star trajectories at the Galactic Center. EPJ Web of Conferences. 2017;138:UNSP 01010
Zakharov Alexander F., Jovanović Predrag, Borka Duško, Borka Jovanović Vesna, "Graviton mass bounds from an analysis of bright star trajectories at the Galactic Center" EPJ Web of Conferences, 138 (2017):UNSP 01010,
https://doi.org/10.1051/epjconf/201713801010 .
7
7
4

Dispersion and damping of the interband pi plasmon in graphene grown on Cu(111) foils

Politano, Antonio; Radović, Ivan; Borka, Duško; Miskovic, Z. L.; Yu, H. K.; Farias, D.; Chiarello, G.

(2017)

TY  - JOUR
AU  - Politano, Antonio
AU  - Radović, Ivan
AU  - Borka, Duško
AU  - Miskovic, Z. L.
AU  - Yu, H. K.
AU  - Farias, D.
AU  - Chiarello, G.
PY  - 2017
UR  - http://vinar.vin.bg.ac.rs/handle/123456789/1414
AB  - By means of angle-resolved electron energy loss spectroscopy, we have measured the interband it plasmon in high-quality graphene grown on peeled-off epitaxial Cu(111) foils. Experimental loss spectra have been reproduced by means of a hydrodynamic model. The dispersion relation of the plasmon frequency shows a nearly-flat dispersion up to a critical wave-vector of 0.3 angstrom(-1). We propose that the observed behavior could be originated by confinement effects in ripples in the strained graphene sheet. Strain also limits the dispersion at higher momenta, as a consequence of the increased effective mass of charge carriers. The analysis of momentum dependence of the line-width and of the inverse quality factor indicates that damping processes are dominated by decay in electron-hole pairs via indirect interband transitions. (C) 2016 Elsevier Ltd. All rights reserved.
T2  - Carbon
T1  - Dispersion and damping of the interband pi plasmon in graphene grown on Cu(111) foils
VL  - 114
SP  - 70
EP  - 76
DO  - 10.1016/j.carbon.2016.11.073
ER  - 
@article{
author = "Politano, Antonio and Radović, Ivan and Borka, Duško and Miskovic, Z. L. and Yu, H. K. and Farias, D. and Chiarello, G.",
year = "2017",
url = "http://vinar.vin.bg.ac.rs/handle/123456789/1414",
abstract = "By means of angle-resolved electron energy loss spectroscopy, we have measured the interband it plasmon in high-quality graphene grown on peeled-off epitaxial Cu(111) foils. Experimental loss spectra have been reproduced by means of a hydrodynamic model. The dispersion relation of the plasmon frequency shows a nearly-flat dispersion up to a critical wave-vector of 0.3 angstrom(-1). We propose that the observed behavior could be originated by confinement effects in ripples in the strained graphene sheet. Strain also limits the dispersion at higher momenta, as a consequence of the increased effective mass of charge carriers. The analysis of momentum dependence of the line-width and of the inverse quality factor indicates that damping processes are dominated by decay in electron-hole pairs via indirect interband transitions. (C) 2016 Elsevier Ltd. All rights reserved.",
journal = "Carbon",
title = "Dispersion and damping of the interband pi plasmon in graphene grown on Cu(111) foils",
volume = "114",
pages = "70-76",
doi = "10.1016/j.carbon.2016.11.073"
}
Politano, A., Radović, I., Borka, D., Miskovic, Z. L., Yu, H. K., Farias, D.,& Chiarello, G. (2017). Dispersion and damping of the interband pi plasmon in graphene grown on Cu(111) foils.
Carbon, 114, 70-76.
https://doi.org/10.1016/j.carbon.2016.11.073
Politano A, Radović I, Borka D, Miskovic ZL, Yu HK, Farias D, Chiarello G. Dispersion and damping of the interband pi plasmon in graphene grown on Cu(111) foils. Carbon. 2017;114:70-76
Politano Antonio, Radović Ivan, Borka Duško, Miskovic Z. L., Yu H. K., Farias D., Chiarello G., "Dispersion and damping of the interband pi plasmon in graphene grown on Cu(111) foils" Carbon, 114 (2017):70-76,
https://doi.org/10.1016/j.carbon.2016.11.073 .
17
19
19

Electron transmission through a macroscopic platinum capillary

Borka, Duško; Borka Jovanović, Vesna; Lemell, Christoph; Tokesi, Karoly

(2017)

TY  - JOUR
AU  - Borka, Duško
AU  - Borka Jovanović, Vesna
AU  - Lemell, Christoph
AU  - Tokesi, Karoly
PY  - 2017
UR  - http://vinar.vin.bg.ac.rs/handle/123456789/7180
AB  - We present simulations for electron transmission through a platinum macrocapillary (diameter d = 3.3 mm, length l = 48 mm) using classical transport theory. Both elastic and inelastic scattering events of primary electrons colliding with the inner wall of the capillary are taken into account. We also model the generation and transport of secondary electrons inside the material. We find excellent agreement of our simulated electron-energy spectra with recent experimental data for 200 eV primary electrons. (C) 2017 Elsevier B.V. All rights reserved.
T2  - Nuclear Instruments and Methods in Physics Research. Section B: Beam Interactions with Materials and Atoms
T1  - Electron transmission through a macroscopic platinum capillary
VL  - 406
SP  - 413
EP  - 416
DO  - 10.1016/j.nimb.2017.02.024
ER  - 
@article{
author = "Borka, Duško and Borka Jovanović, Vesna and Lemell, Christoph and Tokesi, Karoly",
year = "2017",
url = "http://vinar.vin.bg.ac.rs/handle/123456789/7180",
abstract = "We present simulations for electron transmission through a platinum macrocapillary (diameter d = 3.3 mm, length l = 48 mm) using classical transport theory. Both elastic and inelastic scattering events of primary electrons colliding with the inner wall of the capillary are taken into account. We also model the generation and transport of secondary electrons inside the material. We find excellent agreement of our simulated electron-energy spectra with recent experimental data for 200 eV primary electrons. (C) 2017 Elsevier B.V. All rights reserved.",
journal = "Nuclear Instruments and Methods in Physics Research. Section B: Beam Interactions with Materials and Atoms",
title = "Electron transmission through a macroscopic platinum capillary",
volume = "406",
pages = "413-416",
doi = "10.1016/j.nimb.2017.02.024"
}
Borka, D., Borka Jovanović, V., Lemell, C.,& Tokesi, K. (2017). Electron transmission through a macroscopic platinum capillary.
Nuclear Instruments and Methods in Physics Research. Section B: Beam Interactions with Materials and Atoms, 406, 413-416.
https://doi.org/10.1016/j.nimb.2017.02.024
Borka D, Borka Jovanović V, Lemell C, Tokesi K. Electron transmission through a macroscopic platinum capillary. Nuclear Instruments and Methods in Physics Research. Section B: Beam Interactions with Materials and Atoms. 2017;406:413-416
Borka Duško, Borka Jovanović Vesna, Lemell Christoph, Tokesi Karoly, "Electron transmission through a macroscopic platinum capillary" Nuclear Instruments and Methods in Physics Research. Section B: Beam Interactions with Materials and Atoms, 406 (2017):413-416,
https://doi.org/10.1016/j.nimb.2017.02.024 .
1
2
3

Channeling of protons through radial deformed carbon nanotubes

Borka Jovanović, Vesna; Borka, Duško; Galijaš, Sava M. D.

(2017)

TY  - JOUR
AU  - Borka Jovanović, Vesna
AU  - Borka, Duško
AU  - Galijaš, Sava M. D.
PY  - 2017
UR  - http://vinar.vin.bg.ac.rs/handle/123456789/1543
AB  - In this paper we have presented a theoretical investigation of the channeling of 1 GeV protons with the radial deformed (10, 0) single-wall carbon nanotubes (SWNTs). We have calculated channeling potential within the deformed nanotubes. For the first time we presented theoretically obtained spatial and. angular distributions of channeled protons with radially deformed SWNT. We used a Monte Carlo (MC) simulation technique. We show that the spatial and angular distributions depend strongly of level of radial deformation of nanotube. These results may be useful for nanotube characterization and production and guiding of nanosized ion beams. (C) 2017 Elsevier B.V. All rights reserved.
T2  - Physics Letters A
T1  - Channeling of protons through radial deformed carbon nanotubes
VL  - 381
IS  - 19
SP  - 1687
EP  - 1692
DO  - 10.1016/j.physleta.2017.03.029
ER  - 
@article{
author = "Borka Jovanović, Vesna and Borka, Duško and Galijaš, Sava M. D.",
year = "2017",
url = "http://vinar.vin.bg.ac.rs/handle/123456789/1543",
abstract = "In this paper we have presented a theoretical investigation of the channeling of 1 GeV protons with the radial deformed (10, 0) single-wall carbon nanotubes (SWNTs). We have calculated channeling potential within the deformed nanotubes. For the first time we presented theoretically obtained spatial and. angular distributions of channeled protons with radially deformed SWNT. We used a Monte Carlo (MC) simulation technique. We show that the spatial and angular distributions depend strongly of level of radial deformation of nanotube. These results may be useful for nanotube characterization and production and guiding of nanosized ion beams. (C) 2017 Elsevier B.V. All rights reserved.",
journal = "Physics Letters A",
title = "Channeling of protons through radial deformed carbon nanotubes",
volume = "381",
number = "19",
pages = "1687-1692",
doi = "10.1016/j.physleta.2017.03.029"
}
Borka Jovanović, V., Borka, D.,& Galijaš, S. M. D. (2017). Channeling of protons through radial deformed carbon nanotubes.
Physics Letters A, 381(19), 1687-1692.
https://doi.org/10.1016/j.physleta.2017.03.029
Borka Jovanović V, Borka D, Galijaš SMD. Channeling of protons through radial deformed carbon nanotubes. Physics Letters A. 2017;381(19):1687-1692
Borka Jovanović Vesna, Borka Duško, Galijaš Sava M. D., "Channeling of protons through radial deformed carbon nanotubes" Physics Letters A, 381, no. 19 (2017):1687-1692,
https://doi.org/10.1016/j.physleta.2017.03.029 .
4
6
5

Excitation of plasmon wakes in two-dimensional electron systems by moving external charged particles

Radović, Ivan; Song, Yuan-Hong; Zhang, Ying-Ying; Borka, Duško; Miskovic, Zoran L.

(2017)

TY  - JOUR
AU  - Radović, Ivan
AU  - Song, Yuan-Hong
AU  - Zhang, Ying-Ying
AU  - Borka, Duško
AU  - Miskovic, Zoran L.
PY  - 2017
UR  - http://vinar.vin.bg.ac.rs/handle/123456789/1518
AB  - We use the dielectric response formalism to explore the wake effect due to excitation of the sheet plasmons in graphene and in a two-dimensional (2D) electron gas with a parabolic energy band, caused by an externally moving charged particle. Using the random phase approximation to obtain the relevant polarisation functions, we have found similarities as well as some differences in the V-shaped wake patterns that result from different structures of the single-particle excitation spectra in those two electron systems. While both systems exhibit a velocity threshold for the charged particle to be able to excite a wake, graphene shows some irregularities in the wake oscillations behind that particle, whereas the 2D electron gas exhibits a larger opening angle of its V-shaped wake.
T2  - Radiation Effects and Defects in Solids
T1  - Excitation of plasmon wakes in two-dimensional electron systems by moving external charged particles
VL  - 172
IS  - 1-2
SP  - 90
EP  - 99
DO  - 10.1080/10420150.2017.1286661
ER  - 
@article{
author = "Radović, Ivan and Song, Yuan-Hong and Zhang, Ying-Ying and Borka, Duško and Miskovic, Zoran L.",
year = "2017",
url = "http://vinar.vin.bg.ac.rs/handle/123456789/1518",
abstract = "We use the dielectric response formalism to explore the wake effect due to excitation of the sheet plasmons in graphene and in a two-dimensional (2D) electron gas with a parabolic energy band, caused by an externally moving charged particle. Using the random phase approximation to obtain the relevant polarisation functions, we have found similarities as well as some differences in the V-shaped wake patterns that result from different structures of the single-particle excitation spectra in those two electron systems. While both systems exhibit a velocity threshold for the charged particle to be able to excite a wake, graphene shows some irregularities in the wake oscillations behind that particle, whereas the 2D electron gas exhibits a larger opening angle of its V-shaped wake.",
journal = "Radiation Effects and Defects in Solids",
title = "Excitation of plasmon wakes in two-dimensional electron systems by moving external charged particles",
volume = "172",
number = "1-2",
pages = "90-99",
doi = "10.1080/10420150.2017.1286661"
}
Radović, I., Song, Y., Zhang, Y., Borka, D.,& Miskovic, Z. L. (2017). Excitation of plasmon wakes in two-dimensional electron systems by moving external charged particles.
Radiation Effects and Defects in Solids, 172(1-2), 90-99.
https://doi.org/10.1080/10420150.2017.1286661
Radović I, Song Y, Zhang Y, Borka D, Miskovic ZL. Excitation of plasmon wakes in two-dimensional electron systems by moving external charged particles. Radiation Effects and Defects in Solids. 2017;172(1-2):90-99
Radović Ivan, Song Yuan-Hong, Zhang Ying-Ying, Borka Duško, Miskovic Zoran L., "Excitation of plasmon wakes in two-dimensional electron systems by moving external charged particles" Radiation Effects and Defects in Solids, 172, no. 1-2 (2017):90-99,
https://doi.org/10.1080/10420150.2017.1286661 .
1
1
1

Trajectories of bright stars at the Galactic Center as a tool to evaluate a graviton mass

Zakharov, Alexander F.; Jovanović, Predrag; Borka, Duško; Borka Jovanović, Vesna

(2016)

TY  - CONF
AU  - Zakharov, Alexander F.
AU  - Jovanović, Predrag
AU  - Borka, Duško
AU  - Borka Jovanović, Vesna
PY  - 2016
UR  - http://vinar.vin.bg.ac.rs/handle/123456789/7119
AB  - Scientists worked in Saint-Petersburg (Petrograd, Leningrad) played the extremely important role in creation of scientific school and development of general relativity in Russia. Very recently LIGO collaboration discovered gravitational waves [1] predicted 100 years ago by A. Einstein. In the papers reporting about this discovery, the joint LIGO and VIRGO team presented an upper limit on graviton mass such as m(g) LT 1.2 x 10(-22) eV [1, 2]. The authors concluded that their observational data do not show violations of classical general relativity because the graviton mass limit is very small. We show that an analysis of bright star trajectories could bound graviton mass with a comparable accuracy with accuracies reached with gravitational wave interferometers and expected with forthcoming pulsar timing observations for gravitational wave detection. This analysis gives an opportunity to treat observations of bright stars near the Galactic Center as a tool for an evaluation specific parameters of the black hole and also to obtain constraints on the fundamental gravity law such as a modifications of Newton gravity law in a weak field approximation. In that way, based on a potential reconstruction at the Galactic Center we give a bounds on a graviton mass.
C3  - EPJ Web of Conferences
T1  - Trajectories of bright stars at the Galactic Center as a tool to evaluate a graviton mass
VL  - 125
DO  - 10.1051/epjconf/201612501011
ER  - 
@conference{
author = "Zakharov, Alexander F. and Jovanović, Predrag and Borka, Duško and Borka Jovanović, Vesna",
year = "2016",
url = "http://vinar.vin.bg.ac.rs/handle/123456789/7119",
abstract = "Scientists worked in Saint-Petersburg (Petrograd, Leningrad) played the extremely important role in creation of scientific school and development of general relativity in Russia. Very recently LIGO collaboration discovered gravitational waves [1] predicted 100 years ago by A. Einstein. In the papers reporting about this discovery, the joint LIGO and VIRGO team presented an upper limit on graviton mass such as m(g) LT 1.2 x 10(-22) eV [1, 2]. The authors concluded that their observational data do not show violations of classical general relativity because the graviton mass limit is very small. We show that an analysis of bright star trajectories could bound graviton mass with a comparable accuracy with accuracies reached with gravitational wave interferometers and expected with forthcoming pulsar timing observations for gravitational wave detection. This analysis gives an opportunity to treat observations of bright stars near the Galactic Center as a tool for an evaluation specific parameters of the black hole and also to obtain constraints on the fundamental gravity law such as a modifications of Newton gravity law in a weak field approximation. In that way, based on a potential reconstruction at the Galactic Center we give a bounds on a graviton mass.",
journal = "EPJ Web of Conferences",
title = "Trajectories of bright stars at the Galactic Center as a tool to evaluate a graviton mass",
volume = "125",
doi = "10.1051/epjconf/201612501011"
}
Zakharov, A. F., Jovanović, P., Borka, D.,& Borka Jovanović, V. (2016). Trajectories of bright stars at the Galactic Center as a tool to evaluate a graviton mass.
EPJ Web of Conferences, 125.
https://doi.org/10.1051/epjconf/201612501011
Zakharov AF, Jovanović P, Borka D, Borka Jovanović V. Trajectories of bright stars at the Galactic Center as a tool to evaluate a graviton mass. EPJ Web of Conferences. 2016;125
Zakharov Alexander F., Jovanović Predrag, Borka Duško, Borka Jovanović Vesna, "Trajectories of bright stars at the Galactic Center as a tool to evaluate a graviton mass" EPJ Web of Conferences, 125 (2016),
https://doi.org/10.1051/epjconf/201612501011 .
10
11
11

Interband plasmons in supported graphene on metal substrates: Theory and experiments

Politano, Antonio; Radović, Ivan; Borka, Duško; Miskovic, Z. L.; Chiarello, G.

(2016)

TY  - JOUR
AU  - Politano, Antonio
AU  - Radović, Ivan
AU  - Borka, Duško
AU  - Miskovic, Z. L.
AU  - Chiarello, G.
PY  - 2016
UR  - http://vinar.vin.bg.ac.rs/handle/123456789/842
AB  - We present a theoretical modeling of the energy-loss spectroscopy data for monolayer graphene (MLG) supported by Pt(111), Ru(0001) and Ni(111) substrates. To reproduce the experimental loss function, we have used a two-dimensional, two-fluid hydrodynamic model for interband transitions of graphenes pi and sigma electrons and an empirical Drude-Lorentz model in the local approximation for metal substrates. The electronic response from the visible to the ultraviolet frequency range has been nicely reproduced for MLG/Pt(111) and MLG/Ru(0001). For graphene nanodomes on Ru(0001), the loss function of valleys shows an additional mode at 8-9 eV. By contrast, this models fails for the case of MLG/Ni(111), presumably due to the strong hybridization between the pi states of graphene and the d bands of Ni, which is not accounted for in the model. (C) 2015 Elsevier Ltd. All rights reserved.
T2  - Carbon
T1  - Interband plasmons in supported graphene on metal substrates: Theory and experiments
VL  - 96
SP  - 91
EP  - 97
DO  - 10.1016/j.carbon.2015.09.053
ER  - 
@article{
author = "Politano, Antonio and Radović, Ivan and Borka, Duško and Miskovic, Z. L. and Chiarello, G.",
year = "2016",
url = "http://vinar.vin.bg.ac.rs/handle/123456789/842",
abstract = "We present a theoretical modeling of the energy-loss spectroscopy data for monolayer graphene (MLG) supported by Pt(111), Ru(0001) and Ni(111) substrates. To reproduce the experimental loss function, we have used a two-dimensional, two-fluid hydrodynamic model for interband transitions of graphenes pi and sigma electrons and an empirical Drude-Lorentz model in the local approximation for metal substrates. The electronic response from the visible to the ultraviolet frequency range has been nicely reproduced for MLG/Pt(111) and MLG/Ru(0001). For graphene nanodomes on Ru(0001), the loss function of valleys shows an additional mode at 8-9 eV. By contrast, this models fails for the case of MLG/Ni(111), presumably due to the strong hybridization between the pi states of graphene and the d bands of Ni, which is not accounted for in the model. (C) 2015 Elsevier Ltd. All rights reserved.",
journal = "Carbon",
title = "Interband plasmons in supported graphene on metal substrates: Theory and experiments",
volume = "96",
pages = "91-97",
doi = "10.1016/j.carbon.2015.09.053"
}
Politano, A., Radović, I., Borka, D., Miskovic, Z. L.,& Chiarello, G. (2016). Interband plasmons in supported graphene on metal substrates: Theory and experiments.
Carbon, 96, 91-97.
https://doi.org/10.1016/j.carbon.2015.09.053
Politano A, Radović I, Borka D, Miskovic ZL, Chiarello G. Interband plasmons in supported graphene on metal substrates: Theory and experiments. Carbon. 2016;96:91-97
Politano Antonio, Radović Ivan, Borka Duško, Miskovic Z. L., Chiarello G., "Interband plasmons in supported graphene on metal substrates: Theory and experiments" Carbon, 96 (2016):91-97,
https://doi.org/10.1016/j.carbon.2015.09.053 .
21
23
22