Heterotic NS5-branes from closed string tachyon condensation

TL;DR

This paper demonstrates how heterotic NS5-branes can be constructed as topological solitons via closed string tachyon condensation in supercritical heterotic string theory, linking gauge bundles and geometry.

Contribution

It introduces a novel construction of heterotic NS5-branes using tachyon condensation, extending the K-theoretical framework to supercritical heterotic strings.

Findings

Heterotic NS5-branes can be realized as topological solitons.

Tachyon condensation removes extra dimensions in supercritical heterotic strings.

Modified Bianchi identity is essential for the construction.

Abstract

We show how to construct the familiar heterotic NS5 brane as a topological soliton in a supercritical version of heterotic string theory. Closed string tachyon condensation removes the extra dimensions, leaving the NS5 in 10d, in a process highly reminiscent of the K-theoretical description of type II D-branes, but linking non-trivial gauge bundles and geometry. The construction requires a modification of the anomalous Bianchi identity for $H_3$ in supercritical heterotic string theory. We give various proofs for the existence of this modification.