Non-BPS Branes on a Calabi-Yau Threefold and Bose-Fermi Degeneracy

TL;DR

This paper investigates non-BPS D-branes on Calabi-Yau threefolds, revealing specific moduli space points where boson-fermion degeneracy occurs, enabling non-supersymmetric gauge theories without inter-brane forces.

Contribution

It identifies special moduli space points where non-BPS branes exhibit exact boson-fermion degeneracy, allowing for stable, non-supersymmetric gauge theories.

Findings

Degeneracy occurs at specific Calabi-Yau moduli values.

No force between non-BPS D-branes at degeneracy points.

Potential for constructing non-supersymmetric gauge theories.

Abstract

We consider the spectrum of open strings for non-BPS D-brane configuration in type II string theory on a Calabi-Yau threefold. In general, there is no degeneracy between bosonic and fermionic states. However we find special values for the moduli space of Calabi-Yau threefolds there are non-BPS brane configurations which have an exact degeneracy between bosonic and fermionic states. For these values there is no force between pairs of non-BPS D-branes. This gives rise to a possibility of building diverse non-supersymmetric gauge field theories on the brane world-volume. We use the approach recently elaborated by Gaberdiel and Sen.