Event Horizon Telescope Observations as Probes for Quantum Structure of Astrophysical Black Holes

Understand

The need for a consistent quantum evolution for black holes has led to proposals that their semiclassical description is modified not just near the singularity, but at horizon or larger scales.

• If such modifications extend beyond the horizon, they influence regions accessible to distant observeration.
• Natural candidates for these modifications behave like metric fluctuations, with characteristic length and time scales set by the horizon radius.
• We investigate the possibility of using the Event Horizon Telescope to observe these effects, if they have a strength sufficient to make quantum evolution consistent with unitarity.