Possible Astrophysical Observables of Quantum Gravity Effects near Black
  Holes
  Recent implications of results from quantum information theory applied to
black holes has led to the confusing conclusions that requires either
abandoning the equivalence principle (e.g. the firewall picture), or the
no-hair theorem (e.g. the fuzzball picture), or even more unpalatable options.
The recent discovery of a pulsar orbiting a black hole opens up new
possibilities for tests of theories of gravity. We examine possible
observational effects of semiclassical quantum gravity in the vicinity of black
holes, as probed by pulsars and event horizon telescope imaging of flares.
Pulsar radiation is observable at wavelengths only two orders of magnitude
shorter than the Hawking radiation, so precision interferometry of lensed
pulsar images may shed light on the quantum gravitational processes and
interaction of Hawking radiation with the spacetime near the black hole. This
paper discusses the impact on the pulsar radiation interference pattern, which
is observable through the modulation index in the foreseeable future, and
discusses a possible classical limit of BHC.
