D branes in background fluxes and Nielsen-Olesen instabilities

TL;DR

This paper investigates the instability of Dp branes in backgrounds with RR magnetic fluxes, showing that high-spin states can become tachyonic at critical flux levels, indicating a potential vacuum instability.

Contribution

It constructs a back-reacted background with RR fluxes to identify tachyonic Dp brane states and derives their energy spectrum, extending Nielsen-Olesen instability concepts to string theory.

Findings

Identifies tachyonic Dp brane states in RR flux backgrounds.

Derives the energy spectrum for these states.

Shows high-spin Dp states become light at critical fluxes.

Abstract

In quantum field theory, charged particles with spin $\geq 1$ may become tachyonic in the present of magnetic fluxes above some critical field, signaling an instability of the vacuum. The phenomenon is generic, in particular, similar instabilities are known to exist in open and closed string theory, where a spinning string state can become tachyonic above a critical field. In compactifications involving RR fluxes $F_{p+2}$, the quantum states which could become tachyonic by the same Nielsen-Olesen mechanism are Dp branes. By constructing an appropriate background with RR magnetic flux that takes into account back-reaction, we identify the possible tachyonic Dp brane states and compute the formula for the energy spectrum in a sector. More generally, we argue that in any background RR magnetic flux, there are high spin Dp quantum states which become very light at critical fields.