Stable Vacua for Tachyonic Strings

TL;DR

This paper identifies (meta)stable, lower-dimensional vacua for all known tachyonic superstring theories, revealing new solutions with specific gauge groups and no moduli, challenging previous assumptions about their instability.

Contribution

It provides the first comprehensive identification of stable vacua for all known tachyonic superstrings, including novel solutions in dimensions 6, 8, and 9 with specific gauge groups.

Findings

All tachyonic superstrings have (meta)stable vacua in lower dimensions.

Discovered vacua with gauge groups E7×E7, SU(16), and E8.

Vacua have positive vacuum energy and no moduli.

Abstract

In addition to the familiar string theories with spacetime supersymmetry, there exist a number of non-supersymmetric ten-dimensional superstrings. Nearly all of these theories have closed string tachyons, indicating a misidentification of the vacuum around which they are to be quantized. In this work, we identify (meta)stable vacua for all known tachyonic superstrings. These vacua are all lower-dimensional, with most of them being familiar two-dimensional string theories. However, there are also intriguing examples of solutions in dimensions 6, 8, and 9, with respective gauge groups $E_7 \times E_7$, $SU(16)$, and $E_8$. These special vacua have positive vacuum energy and no moduli.