Seeing dark matter via acceleration radiation

Despite constituting a noteworthy $\sim 27\%$ share of the total energy budget of our Universe, dark matter (DM) has thus far eluded direct observations. Owing to its pervasive nature, there is a sincere expectation that astrophysical black holes (BHs) encompassed by DM should leave distinctive imprints on the gravitational waves arising from BH mergers. Theoretical models of DM present a diverse landscape of possibilities, with perfect fluid dark matter (PFDM) emerging as a recent and notably intriguing candidate model. In this work, utilizing the established quantum optical approach, we investigate the possibility of catching DM signatures via acceleration radiation emitted by a freely falling detector (e.g., an atom) within a PFDM-surrounded Schwarzschild BH. The setup involves a Casimir-type apparatus where the detector interacts with the field, and this situation induces excitations in the detector in a manner consistent with Unruh effect. We observe that our DM candidate, while making classical contributions to spacetime geometry, has the potential to leave quantum imprints in the radiation flux. Notably, it is observed that, in comparison to a pure Schwarzschild BH, PFDM can markedly reduce particle emission as long as its density remains below a critical threshold, and vice versa. Given the lessons we have learnt from realizing cosmological phenomena in simulated laboratory conditions, there is a remote possibility that such study may perhaps provide insights (to whatever degree) into the future table-top experiments in analog gravity paradigm.