Eddington-inspired Born-Infeld gravity: nuclear physics constraints and the validity of the continuous fluid approximation

TL;DR

This paper examines the non-relativistic limit of Eddington-inspired Born-Infeld gravity, deriving bounds on its parameters from nuclear physics constraints and discussing the validity of the continuous fluid approximation in astrophysical contexts.

Contribution

It provides new bounds on the theory's parameters based on nuclear physics and critically analyzes the applicability of the continuous fluid approximation.

Findings

Strong bounds on the parameter  from nuclear physics constraints.

The continuous fluid approximation is valid for smooth density distributions.

The approximation should be validated at a quantum level.

Abstract

In this paper we investigate the classical non-relativistic limit of the Eddington-inspired Born-Infeld theory of gravity. We show that strong bounds on the value of the only additional parameter of the theory \kappa, with respect to general relativity, may be obtained by requiring that gravity plays a subdominant role compared to electromagnetic interactions inside atomic nuclei. We also discuss the validity of the continuous fluid approximation used in this and other astrophysical and cosmological studies. We argue that although the continuous fluid approximation is expected to be valid in the case of sufficiently smooth density distributions, its use should eventually be validated at a quantum level.