Superball of Strings
Abstract
I solve the equations of the low-energy limit of string theory to obtain a solution corresponding to a microcanonical ensemble of highly-excited superstrings. This ``Superball of Strings'' is a static, spherically symmetric ``fuzzball'' of BPS strings with a size set by a random walk scaling. The solution can be embedded in string theory in a significant part of parameter space. While the solution does not constitute a Lorentzian interpretation for a Euclidean, horizonless solution by Chen, Maldacena, and Witten, a few connections are noted. A singular extremal black hole and the Superball of Strings exist as Supergravity solutions with the same asymptotic boundary conditions; however, I argue that the latter describes generic BPS microstates.
Cite
@article{arxiv.2601.09785,
title = {Superball of Strings},
author = {Yoav Zigdon},
journal= {arXiv preprint arXiv:2601.09785},
year = {2026}
}
Comments
32 pages, V2: added a comment about the sizes of solutions in different ensembles; matches to a published version