Fuzzball geometries and higher derivative corrections for extremal holes

TL;DR

This paper investigates the geometries of extremal black hole microstates, showing that higher derivative corrections from string modes do not lead to horizons, supporting the fuzzball proposal for black hole microstates.

Contribution

It provides evidence that 3-charge microstate geometries are capped and free of horizons even after considering higher derivative string corrections.

Findings

Travel time of 3-charge geometries matches dual CFT predictions

Higher derivative corrections are bounded and do not form horizons

Caps in microstate geometries prevent horizon formation

Abstract

2-charge D1-D5 microstates are described by geometries which end in `caps' near r=0; these caps reflect infalling quanta back in finite time. We estimate the travel time for 3-charge geometries in 4-D, and find agreement with the dual CFT. This agreement supports a picture of `caps' for 3-charge geometries. We argue that higher derivative corrections to such geometries arise from string winding modes. We then observe that the `capped' geometries have no noncontractible circles, so these corrections remain bounded everywhere and cannot create a horizon or singularity.