A Casimir-like probe for 4D Einstein-Gauss-Bonnet gravity

TL;DR

This paper investigates how quantum field interactions near black holes in 4D Einstein-Gauss-Bonnet gravity differ from Einstein gravity, revealing that the Gauss-Bonnet coupling parameter influences acceleration radiation intensity.

Contribution

It introduces a novel Casimir-like probe using an Unruh-DeWitt detector to study quantum effects in 4D EGB black hole spacetimes, highlighting the impact of higher-curvature terms.

Findings

Radiation enhancement for negative Gauss-Bonnet coupling $oldsymbol{eta}$

Radiation suppression for positive $oldsymbol{eta}$

Higher-curvature effects alter quantum field behavior near black holes

Abstract

Virtual transitions in a Casimir-like configuration are utilized to probe quantum aspects of four-dimensional Einstein-Gauss-Bonnet (4D EGB) gravity. This study employs a quantum optics-based approach, wherein an Unruh-DeWitt detector (modeled as a two-level atom) follows a radial timelike geodesic, falling freely into an uncharged, nonrotating black hole described by 4D EGB gravity, becoming thermalized in the usual Unruh manner. The black hole, asymptotically Minkowskian, is enclosed by a Casimir boundary proximate to its horizon, serving as a source for accelerated field modes that interact with the infalling detector. Observations are conducted by an asymptotic infinity observer, assuming a Boulware field state. Our numerical analysis reveals that, unlike in Einstein gravity, black holes in 4D EGB gravity can either enhance or suppress the intensity of acceleration radiation, contingent upon the Gauss-Bonnet coupling parameter $\alpha$. Specifically, we observe radiation enhancement for negative $\alpha$ and suppression for positive $\alpha$. These findings offer substantial insights into quantifying the influence of higher-curvature contributions on the behavior of quantum fields in black hole geometries within a 4D spacetime.