A Stellar Constraint on Eddington-inspired Born–Infeld Gravity from Cataclysmic Variable Binaries

• Published in: The Astrophysical journal Vol. 924; no. 1; pp. 20 - 27
• Main Authors: Banerjee, Pritam, Garain, Debojyoti, Paul, Suvankar, Shaikh, Rajibul, Sarkar, Tapobrata
• Format: Journal Article
• Language: English
• Published: Philadelphia The American Astronomical Society 01.01.2022; IOP Publishing
• Subjects: Astrophysical processes; Astrophysics; Cataclysmic variable stars; Cataclysmic variables; Confidence intervals; General relativity; Gravitational collapse; Gravity theories; Monte Carlo simulation; Numerical schemes; Poisson equation; Relativity; Stellar models; Theory of relativity; White dwarf stars
• ISSN: 0004-637X; 1538-4357
• DOI: 10.3847/1538-4357/ac324f

Abstract Eddington-inspired Born–Infeld gravity is an important modification of Einstein’s general relativity, which can give rise to nonsingular cosmologies at the classical level, and avoid the end-stage singularity in a gravitational collapse process. In the Newtonian limit, this theory gives rise to a modified Poisson’s equation, as a consequence of which stellar observables acquire model dependent corrections, compared to the ones computed in the low energy limit of general relativity. This can in turn be used to establish astrophysical constraints on the theory. Here, we obtain such a constraint using observational data from cataclysmic variable binaries. In particular, we consider the tidal disruption limit of the secondary star by a white dwarf primary. The Roche lobe filling condition of this secondary star is used to compute stellar observables in the modified gravity theory in a numerical scheme. These are then contrasted with the values obtained by using available data on these objects, via a Monte Carlo error progression method. This way, we are able to constrain the theory within the 5 σ confidence level.