Testing quantum black holes with gravitational waves

Abstract

We argue that near-future detections of gravitational waves from merging black hole binaries can test a long-standing proposal, originally due Bekenstein and Mukhanov, that the areas of black hole horizons are quantized in integer multiples of the Planck area times an O(1) dimensionless constant α. This condition quantizes the frequency of radiation that can be absorbed or emitted by a black hole. If this quantization applies to the "ring down" gravitational radiation emitted immediately after a black hole merger, a single measurement consistent with the predictions of classical general relativity would rule out most or all (depending on the spin of the hole) of the extant proposals in the literature for the value of α. A measurement of two such events for final black holes with substantially different spins would rule out the proposal for any α. If the modification of general relativity is confined to the near-horizon region within the hole's light ring and does not affect the initial ring down signal, a detection of "echoes" with characteristic properties could still confirm the proposal.

Testing the nature of dark compact objects: a status report

“…In addition, some physics related to compact objects have a logarithmic dependence on the (reasonably-defined) Planck length [41] (as also discussed below). Curiously, some attempts to quantize the area of BHs predict sizable effects even at a classical level, resulting in precisely the same phenomenology as that discussed in the rest of this review [42][43][44][45][46]. Thus, quantum-gravity effects may be within reach.…”

Mixing of gravitational wave echoes

“…In a pioneer work, Bekenstein and Mukhanov [39,40] have pointed out that the area of BH horizon might be quantized A ∼ (integer)l 2 P (l 2 P is the Planck area). As a result, the wavelength of GWs absorbed or emitted by a BH is also quantized, see also [41]. Recently, in Ref.…”

Prospecting black hole thermodynamics with fractional quantum mechanics

“…Interestingly, the mass spectrum (54) (which includes the standard case (41)) may induce observable signatures that gravitational waves [100][101][102] may inform about. Equation (43) shows that the frequency of the emitted Hawking radiation scales as 1/M.…”