  Virtual transitions in a Casimir-like configuration are utilized to probe
quantum aspects of the recently proposed 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.
