Stable Non-BPS States in String Theory

TL;DR

This paper investigates stable non-BPS states in string theory, demonstrating how duality symmetries can identify their strong coupling behavior and proposing potential origins for these states from non-supersymmetric D-branes.

Contribution

It shows that duality symmetries can be used to identify and calculate masses of stable non-BPS states at strong coupling in string theory.

Findings

Duality symmetries enable identification of non-BPS states at strong coupling.

Masses of certain non-BPS states can be explicitly calculated.

Proposes non-supersymmetric D-branes as potential origins for missing states.

Abstract

Many string theories contain states which are not BPS, but are stable due to charge conservation. In many cases the description of these states in the strong coupling limit remains unknown despite the existence of a weakly coupled dual theory. However, we show that in some cases duality symmetries in string theory do enable us to identify these states in the strong coupling limit and calculate their masses. We also speculate that in some of the other cases the missing states might arise from non-supersymmetric analog of D0-branes.