Phase transition at high supersymmetry breaking scale in string theory

TL;DR

This paper investigates the stability of Minkowski spacetime in heterotic string theory when supersymmetry is spontaneously broken at high scales, revealing a phase transition related to tachyonic instabilities.

Contribution

It demonstrates that high-scale supersymmetry breaking leads to tachyonic instabilities and characterizes the phase space structure of resulting vacua in heterotic string models.

Findings

High supersymmetry breaking scale induces tachyonic modes.

Minkowski spacetime becomes unstable at string-scale supersymmetry breaking.

Phase space analysis of vacua with specific tachyonic modes.

Abstract

When supersymmetry is spontaneously broken at tree level, the spectrum of the heterotic string compactified on orbifolds of tori contains an infinite number of potentially tachyonic modes. We show that this implies instabilities of Minkowski spacetime, when the scale of supersymmetry breaking is of the order of the string scale. We derive the phase space structure of vacua in the case where the tachyonic spectrum contains a mode with trivial momenta and winding numbers along the internal directions not involved in the supersymmetry breaking.