Destabilizing Tachyonic Vacua at or above the BF Bound

TL;DR

This paper investigates the quantum stability of tachyonic vacua in asymptotically AdS space at the BF bound, revealing exact instanton solutions that cause decay and providing a finite decay rate formula.

Contribution

It presents the first exact instanton solutions destabilizing tachyonic vacua at the BF bound and derives an analytic decay rate formula.

Findings

Exact instanton solutions destabilize tachyonic vacua at the BF bound.

Decay rate for these vacua is finite and analytically calculable.

Results refine the understanding of stability conditions for tachyonic states.

Abstract

It is well known that tachyonic vacua in an asymptotically Anti-de Sitter (AdS) space-time are classically stable if the mass squared is at or above the Breitenlohner and Freedman (BF) bound. We study the quantum stability of these tachyonic vacua in terms of instantons. We find a series of exact instanton solutions destabilizing tachyonic state at or above the BF bound in asymptotically AdS space. We also give an analytic formula for the decay rate and show that it is finite. Comparing our result with the well-known algebraic condition for the stability, we discuss stability conditions of tachyonic vacua at or above the BF bound.