Masking a singularity with k-essence fields in an emergent gravity metric

TL;DR

This paper demonstrates that in k-essence theories, certain field configurations can hide gravitational singularities from perturbation observers by altering the emergent metric, especially in Schwarzschild and Reissner-Nordstrom spacetimes.

Contribution

It shows how k-essence fields can mask gravitational singularities in emergent metrics for specific configurations, extending understanding of emergent gravity scenarios.

Findings

Singularities can be hidden from perturbation observers.

Emergent metrics differ from gravitational metrics in k-essence models.

The masking effect applies to Schwarzschild and Reissner-Nordstrom solutions.

Abstract

It is known that dynamical solutions of the $k$-essence equation of motion change the metric for the perturbations around these solutions and the perturbations propagate in an emergent spacetime with metric $\tilde G^{\mu\nu}$ different from the gravitational metric $g^{\mu\nu}$. We show that for observers travelling with the perturbations, there exist field configurations for the lagrangian $L=[{1\over 2}g^{\mu\nu}\nabla_{\mu}\phi\nabla_{\nu}\phi]^{1\over 2}$ for which a singularity in the gravitational metric $g^{\mu\nu}$ can be masked or hidden for such observers. This is shown for the Schwarzschild and the Reissner-Nordstrom metrics.