TY  - JOUR
AU  - Capozziello, Salvatore
AU  - Borka, Duško
AU  - Jovanović, Predrag
AU  - Borka Jovanović, Vesna
PY  - 2014
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/55
AB  - We investigate the possibility of explaining theoretically the observed deviations of S2 star orbit around the Galactic Centre using gravitational potentials derived from modified gravity models in the absence of dark matter. To this aim, an analytic fourth-order theory of gravity, nonminimally coupled with a massive scalar field, is considered. Specifically, the interaction term is given by the analytic functions f(R) and f(R, phi) where R is the Ricci scalar and phi is a scalar field whose meaning can be related to further gravitational degrees of freedom. We simulate the orbit of the S2 star around the Galactic Centre in f(R) (Yukawa-like) and f(R, phi) (Sanders-like) gravity potentials and compare it with New Technology Telescope/Very Large Telescope observations. Our simulations result in strong constraints on the range of gravity interaction. In the case of analytic functions f(R), we are not able to obtain reliable constraints on the derivative constants f(1) and f(2), because the current observations of the S2 star indicated that they may be highly mutually correlated. In the case of analytic functions f(R, phi), we are able to obtain reliable constraints on the derivative constants f(0), f(R), f(RR), f(phi), f(phi phi), and f(phi R). The approach we are proposing seems to be sufficiently reliable to constrain the modified gravity models from stellar orbits around the Galactic Centre.
T2  - Physical Review D
T1  - Constraining extended gravity models by S2 star orbits around the Galactic Centre
VL  - 90
IS  - 4
DO  - 10.1103/PhysRevD.90.044052
ER  - 

@article{
author = "Capozziello, Salvatore and Borka, Duško and Jovanović, Predrag and Borka Jovanović, Vesna",
year = "2014",
abstract = "We investigate the possibility of explaining theoretically the observed deviations of S2 star orbit around the Galactic Centre using gravitational potentials derived from modified gravity models in the absence of dark matter. To this aim, an analytic fourth-order theory of gravity, nonminimally coupled with a massive scalar field, is considered. Specifically, the interaction term is given by the analytic functions f(R) and f(R, phi) where R is the Ricci scalar and phi is a scalar field whose meaning can be related to further gravitational degrees of freedom. We simulate the orbit of the S2 star around the Galactic Centre in f(R) (Yukawa-like) and f(R, phi) (Sanders-like) gravity potentials and compare it with New Technology Telescope/Very Large Telescope observations. Our simulations result in strong constraints on the range of gravity interaction. In the case of analytic functions f(R), we are not able to obtain reliable constraints on the derivative constants f(1) and f(2), because the current observations of the S2 star indicated that they may be highly mutually correlated. In the case of analytic functions f(R, phi), we are able to obtain reliable constraints on the derivative constants f(0), f(R), f(RR), f(phi), f(phi phi), and f(phi R). The approach we are proposing seems to be sufficiently reliable to constrain the modified gravity models from stellar orbits around the Galactic Centre.",
journal = "Physical Review D",
title = "Constraining extended gravity models by S2 star orbits around the Galactic Centre",
volume = "90",
number = "4",
doi = "10.1103/PhysRevD.90.044052"
}

Capozziello, S., Borka, D., Jovanović, P.,& Borka Jovanović, V.. (2014). Constraining extended gravity models by S2 star orbits around the Galactic Centre. in Physical Review D, 90(4).
https://doi.org/10.1103/PhysRevD.90.044052

Capozziello S, Borka D, Jovanović P, Borka Jovanović V. Constraining extended gravity models by S2 star orbits around the Galactic Centre. in Physical Review D. 2014;90(4).
doi:10.1103/PhysRevD.90.044052 .

Capozziello, Salvatore, Borka, Duško, Jovanović, Predrag, Borka Jovanović, Vesna, "Constraining extended gravity models by S2 star orbits around the Galactic Centre" in Physical Review D, 90, no. 4 (2014),
https://doi.org/10.1103/PhysRevD.90.044052 . .