Probing hybrid modified gravity by stellar motion around Galactic Center
Abstract
We consider possible signatures for the so called hybrid gravity within the Galactic Central Parsec. This modified theory of gravity consists of a superposition of the metric Einstein-Hilbert Lagrangian with an f(R) term constructed a la Palatini and can be easily reduced to an equivalent scalar-tensor theory. Such an approach is introduced in order to cure the shortcomings related to f(R) gravity, in general formulated either in metric or in metric-affine frameworks. Hybrid gravity allows to disentangle the further gravitational degrees of freedom with respect to those of standard General Relativity. The present analysis is based on the S2 star orbital precession around the massive compact dark object at the Galactic Center where the simulated orbits in hybrid modified gravity are compared with astronomical observations. These simulations result with constraints on the range of hybrid gravity interaction parameter phi(0), showing that in the case of S2 star it is between -0.0009 and -...0.0002. At the same time, we are also able to obtain the constraints on the effective mass parameter m(phi), and found that it is between -0.0034 and -0.0025 AU(-1) for S2 star. Furthermore, the hybrid gravity potential induces precession of S2 star orbit in the same direction as General Relativity. In previous papers, we considered other types of extended gravities, like metric power law f(R)proportional to R-n gravity, inducing Yukawa and Sanders-like gravitational potentials, but it seems that hybrid gravity is the best among these models to explain different gravitational phenomena at different astronomical scales. (C) 2016 Elsevier B.V. All rights reserved.
Keywords:
Modified theories of gravity / Experimental tests of gravitational theories / Dark matterSource:
Astroparticle Physics, 2016, 79, 41-48Publisher:
- Elsevier
Funding / projects:
- Gravitation and the large scale structure of the Universe (RS-MESTD-Basic Research (BR or ON)-176003)
- INFN (iniziative specifiche QGSKY), NewCompStar, COST Action [MP1304], Bilateral cooperation between Serbia and Italy Testing Extended Theories of Gravity at different astrophysical scales, INFN (iniziative specifiche TEONGRAV)
DOI: 10.1016/j.astropartphys.2016.03.002
ISSN: 0927-6505; 1873-2852
WoS: 000375809600005
Scopus: 2-s2.0-84962439692
Collections
Institution/Community
VinčaTY - JOUR AU - Borka, Duško AU - Capozziello, Salvatore AU - Jovanović, Predrag AU - Borka Jovanović, Vesna PY - 2016 UR - https://vinar.vin.bg.ac.rs/handle/123456789/1070 AB - We consider possible signatures for the so called hybrid gravity within the Galactic Central Parsec. This modified theory of gravity consists of a superposition of the metric Einstein-Hilbert Lagrangian with an f(R) term constructed a la Palatini and can be easily reduced to an equivalent scalar-tensor theory. Such an approach is introduced in order to cure the shortcomings related to f(R) gravity, in general formulated either in metric or in metric-affine frameworks. Hybrid gravity allows to disentangle the further gravitational degrees of freedom with respect to those of standard General Relativity. The present analysis is based on the S2 star orbital precession around the massive compact dark object at the Galactic Center where the simulated orbits in hybrid modified gravity are compared with astronomical observations. These simulations result with constraints on the range of hybrid gravity interaction parameter phi(0), showing that in the case of S2 star it is between -0.0009 and -0.0002. At the same time, we are also able to obtain the constraints on the effective mass parameter m(phi), and found that it is between -0.0034 and -0.0025 AU(-1) for S2 star. Furthermore, the hybrid gravity potential induces precession of S2 star orbit in the same direction as General Relativity. In previous papers, we considered other types of extended gravities, like metric power law f(R)proportional to R-n gravity, inducing Yukawa and Sanders-like gravitational potentials, but it seems that hybrid gravity is the best among these models to explain different gravitational phenomena at different astronomical scales. (C) 2016 Elsevier B.V. All rights reserved. PB - Elsevier T2 - Astroparticle Physics T1 - Probing hybrid modified gravity by stellar motion around Galactic Center VL - 79 SP - 41 EP - 48 DO - 10.1016/j.astropartphys.2016.03.002 ER -
@article{ author = "Borka, Duško and Capozziello, Salvatore and Jovanović, Predrag and Borka Jovanović, Vesna", year = "2016", abstract = "We consider possible signatures for the so called hybrid gravity within the Galactic Central Parsec. This modified theory of gravity consists of a superposition of the metric Einstein-Hilbert Lagrangian with an f(R) term constructed a la Palatini and can be easily reduced to an equivalent scalar-tensor theory. Such an approach is introduced in order to cure the shortcomings related to f(R) gravity, in general formulated either in metric or in metric-affine frameworks. Hybrid gravity allows to disentangle the further gravitational degrees of freedom with respect to those of standard General Relativity. The present analysis is based on the S2 star orbital precession around the massive compact dark object at the Galactic Center where the simulated orbits in hybrid modified gravity are compared with astronomical observations. These simulations result with constraints on the range of hybrid gravity interaction parameter phi(0), showing that in the case of S2 star it is between -0.0009 and -0.0002. At the same time, we are also able to obtain the constraints on the effective mass parameter m(phi), and found that it is between -0.0034 and -0.0025 AU(-1) for S2 star. Furthermore, the hybrid gravity potential induces precession of S2 star orbit in the same direction as General Relativity. In previous papers, we considered other types of extended gravities, like metric power law f(R)proportional to R-n gravity, inducing Yukawa and Sanders-like gravitational potentials, but it seems that hybrid gravity is the best among these models to explain different gravitational phenomena at different astronomical scales. (C) 2016 Elsevier B.V. All rights reserved.", publisher = "Elsevier", journal = "Astroparticle Physics", title = "Probing hybrid modified gravity by stellar motion around Galactic Center", volume = "79", pages = "41-48", doi = "10.1016/j.astropartphys.2016.03.002" }
Borka, D., Capozziello, S., Jovanović, P.,& Borka Jovanović, V.. (2016). Probing hybrid modified gravity by stellar motion around Galactic Center. in Astroparticle Physics Elsevier., 79, 41-48. https://doi.org/10.1016/j.astropartphys.2016.03.002
Borka D, Capozziello S, Jovanović P, Borka Jovanović V. Probing hybrid modified gravity by stellar motion around Galactic Center. in Astroparticle Physics. 2016;79:41-48. doi:10.1016/j.astropartphys.2016.03.002 .
Borka, Duško, Capozziello, Salvatore, Jovanović, Predrag, Borka Jovanović, Vesna, "Probing hybrid modified gravity by stellar motion around Galactic Center" in Astroparticle Physics, 79 (2016):41-48, https://doi.org/10.1016/j.astropartphys.2016.03.002 . .