Testing gravitational theories using eccentric eclipsing detached binaries

Abstract

In this paper, we compare the effects of different theories of gravitation on the apsidal motion of a sample of eccentric eclipsing detached binary stars. The comparison is performed by using the formalism of the post-Newtonian parametrization to calculate the theoretical advance at periastron and compare it to the observed one, after having considered the effects of the structure and rotation of the involved stars. A variance analysis on the results of this comparison shows that no significant difference can be found due to the effect of the different theories under test with respect to the standard general relativity (GR). It will be possible to observe differences, as we would expect, by checking the observed period variation on a much larger lapse of time. It can also be noted from our results that f(R) theory is the nearest to GR with respect to the other tested theories

Cosmographic Constraints and Cosmic Fluids

“…f (R)-models to describe DE behavior are studied by [105][106][107][108][109][110][111][112][113][114][115][116]. Furthermore, models that satisfy both Solar System and cosmological constraints have been proposed in [117][118][119][120][121][122][123][124][125][126][127][128][129][130][131][132][133]. In particular, since the Newtonian law on large scales undergoes changes in f (R)-gravity, this leaves several interesting observational signatures, such as the modification of rotational curves of a galaxy, galaxy clustering spectra [134][135][136][137][138][139], CMB [118,140] and weak lensing [141,142].…”

Precessing and periodic motions around a black-bounce/traversable wormhole

“…It is no doubt that the anomalous perihelion advance of Mercury belongs to the earliest observational evidences of GR [32] and its next-to-leading-order advance has been examined as well [33][34][35]. Nowadays, the periastron advances of the planets around the Sun [36][37][38][39][40][41][42][43] and other stars [44][45][46][47], of binary stars [48][49][50][51][52][53][54] and of stars around the supermassive black hole in the Galactic Center Sgr A* [55][56][57][58][59][60][61][62][63][64] have been widely adopted and discussed for probing and constraining modified theories of gravity and new physics. Especially, the Schwarzschild precession in the orbit of the star S2 orbiting Sgr A* predicted by GR was just detected by the interferometry GRAVITY [64], paving the way for testing the fundamental theories of gravity and investigating the properties of Sgr A* by making use of the precessing motion of geodesic orbits around various kinds of black holes and other spacetimes.…”

Probing Gravitational Theories with Eccentric Eclipsing Detached Binary Stars

“…We conveniently modified the 'classical' formula by introducing a factor (K T h ) to take into account the dependance on the theory dependent PN terms in order to test the different relativistic theories. [10]:…”

“…the General Relativity ('classical' term), the Nordvedt, the Brans-Dicke theories and the so called f (R) theories that take into account higher order terms of the Ricci scalar R, giving a general expression for the relativistic termω Rel , that contributes to the advance at periastron. Using for the different theories the appropriate values of α T h , α T h , α T h , α T h , ∆ T h and γ T h the numerical values of K T h can be obtained [10]:…”