Superball of strings

A bstract 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.