Fuzzballs and Observations

TL;DR

This paper reviews the potential for observing string theory-based fuzzball microstructures of black holes through gravitational wave and imaging experiments, bridging theoretical models and observational prospects.

Contribution

It provides an overview of fuzzball theory, microstate geometries, and discusses how current and future observations could detect signatures of these string-theoretic black hole models.

Findings

Fuzzball microstructures could produce observable signals in gravitational wave data.

Microstate geometries offer explicit models for horizon-scale black hole microstructure.

Observational experiments may distinguish fuzzballs from classical black holes.

Abstract

The advent of gravitational waves and black hole imaging has opened a new window into probing the horizon scale of black holes. An important question is whether string theory results for black holes can predict interesting and observable features that current and future experiments can probe. In this article I review the budding and exciting research being done on understanding the possibilities of observing signals from fuzzballs, where black holes are replaced by string-theoretic horizon-scale microstructure. In order to be accessible to both string theorists and black hole phenomenologists, I give a brief overview of the relevant observational experiments as well as the fuzzball paradigm in string theory and its explicitly constructable solutions called microstate geometries.