Stringy Tachyonic Instabilities of Non-Supersymmetric Ricci Flat Backgrounds

TL;DR

This paper investigates stringy instabilities in non-supersymmetric Ricci flat backgrounds using worldsheet conformal field theory, revealing tachyons at small radius and negative vacuum energy at large radius.

Contribution

It provides a worldsheet CFT analysis of instabilities in Type II superstring theories on Ricci flat spin 3-manifolds, including their spin structures.

Findings

Presence of stringy tachyons at small radius

Negative 1-loop vacuum energy at large radius

Extension considerations to higher dimensions

Abstract

Superstring/M-theory compactified on compact Ricci flat manifolds have recently been conjectured to exhibit instabilities whenever the metrics do not have special holonomy. We use worldsheet conformal field theory to investigate instabilities of Type II superstring theories on compact, Ricci flat, spin 3-manifolds including a worldsheet description of their spin structures. The instabilities are signalled by the appearance of stringy tachyons at small radius and a negative (1-loop) vacuum energy density at large radius. We briefly discuss the extension to higher dimensions.