D-branes and orientifolds of SO(3)

TL;DR

This paper investigates the properties of D-branes and orientifolds on the SO(3) group manifold, focusing on equatorial branes as projective planes and their associated orientifold projections.

Contribution

It demonstrates the existence of a Dirac-Born-Infeld action on non-orientable equatorial branes and identifies two distinct orientifold projections with identical spacetime effects.

Findings

Dirac-Born-Infeld action defined on equatorial branes

Two orientifold projections with same spacetime action

Equatorial branes are projective planes

Abstract

We study branes and orientifolds on the group manifold of SO(3). We consider particularly the case of the equatorial branes, which are projective planes. We show that a Dirac-Born-Infeld action can be defined on them, although they are not orientable. We find that there are two orientifold projections with the same spacetime action, which differ by their action on equatorial branes.