Thursday, March 05, 2025, 16:00
WHGA/001
Jens Boos, Karlsruhe Insitut of Technology
Abstract:
While general relativity has passed every experimental test to date, it predicts the existence of spacetime singularities: regions where classical physics breaks down, such as the interior of black holes. A key question is whether these singularities are resolved by new physics, and if such new physics can leave observable imprints outside the black hole horizon.
In this talk, I will address this question using a phenomenological model in which short-distance modifications smooth out spacetime singularities. Although such modifications occur at microscopic scales, I will describe three observational settings where black hole observables can be sensitive to such small deviations.
First, X-ray emission from matter orbiting close to the black hole can produce characteristic spectral features. Second, gravitational microlensing events with small source angles probe the near-horizon geometry. Third, black holes formed in the early universe evolve over cosmic timescales, allowing small deviations to accumulate and potentially contribute to dark matter.
Last, I will argue that black holes provide a promising and exciting arena to search for signatures of new physics.