Born–Infeld inspired modifications of gravity
Résumé
General Relativity has shown an outstanding observational success in the scales where it has been directly tested. However, modifications have been intensively explored in the regimes where it seems either incomplete or signals its own limit of validity. In particular, the breakdown of unitarity near the Planck scale strongly suggests that General Relativity needs to be modified at high energies and quantum gravity effects are expected to be important. This is related to the existence of spacetime singularities when the solutions of General Relativity are extrapolated to regimes where curvatures are large. In this sense, Born–Infeld inspired modifications of gravity have shown an extraordinary ability to regularise the gravitational dynamics, leading to non-singular cosmologies and regular black hole spacetimes in a very robust manner and without resorting to quantum gravity effects. This has boosted the interest in these theories in applications to stellar structure, compact objects, inflationary scenarios, cosmological singularities, and black hole and wormhole physics, among others. We review the motivations, various formulations, and main results achieved within these theories, including their observational viability, and provide an overview of current open problems and future research opportunities.
Mots clés
Born–Infeld gravity
Astrophysics
Black holes
Cosmology
Early universe
Compact objects
Singularities
quantum gravity: effect
general relativity: solution
space-time: singularity
space-time: black hole
scale: Planck
energy: high
gravitation
Born-Infeld model
cosmological model
regularization
unitarity
curvature
inflation
structure
formation
star: compact
wormhole