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  - https://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",
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. in 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. in Physical Review D. 2019;99(4):044053.
doi:10.1103/PhysRevD.99.044053 .

Dialektopoulos, Konstantinos F., Borka, Duško, Capozziello, Salvatore, Borka Jovanović, Vesna, Jovanović, Predrag, "Constraining nonlocal gravity by S2 star orbits" in Physical Review D, 99, no. 4 (2019):044053,
https://doi.org/10.1103/PhysRevD.99.044053 . .

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  - https://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",
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. in 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. in Physical Review D. 2019;99(4):044053.
doi:10.1103/PhysRevD.99.044053 .

Dialektopoulos, Konstantinos F., Borka, Duško, Capozziello, Salvatore, Borka Jovanović, Vesna, Jovanović, Predrag, "Constraining nonlocal gravity by S2 star orbits" in Physical Review D, 99, no. 4 (2019):044053,
https://doi.org/10.1103/PhysRevD.99.044053 . .