String dynamics in NS5-F1-P geometries

TL;DR

This paper analyzes string dynamics in NS5-F1-P geometries using an exactly solvable model, revealing the spectrum of excitations, underlying symmetries, and microstructure insights beyond supergravity approximations.

Contribution

It provides an exact worldsheet description of string excitations in fivebrane backgrounds and explores the microstructure through winding sectors and gauge transformations.

Findings

Low-lying spectrum matches supergravity modes

Winding sectors encode string charges and flux transitions

S-matrix reveals hidden fivebrane microstructure

Abstract

String theory dynamics on certain fivebrane supertube backgrounds is described by an exactly solvable null-gauged WZW model. We use this description to compute the spectrum of closed string excitations on the three-charge non-supersymmetric solution found by Jejjala, Madden, Ross and Titchener, as well as its supersymmetric limit. The low-lying spectrum matches that of supergravity modes in the effective geometry and exhibits an underlying group-theoretic structure. Winding sectors describe strings carrying the same charges as the background; processes whereby strings turn into flux or vice-versa are mediated by large gauge transformations on the worldsheet. The S-matrix of such wound strings probes microstructure of the fivebrane source that is hidden in the supergravity approximation.