AdS$_3$ String Stars at Pure NSNS Flux

Abstract

We study Horowitz-Polchinski string stars in pure AdS$_3$ near the Hagedorn temperature using the technique of worldsheet conformal perturbation theory. Since the worldsheet CFT for pure AdS$_3$ is known exactly, our methodology provides a systematic way to construct Horowitz-Polchinski backgrounds to all orders in $\alpha'$. We explicitly construct the leading string star equations in a double expansion in temperature and WZW level $k$ which we then solve numerically.