Intersecting D-Branes on Shift Z2 x Z2 Orientifolds

TL;DR

This paper classifies and analyzes intersecting D-branes on shift Z2 x Z2 orientifolds, revealing how shifts influence topology, orientifold planes, and D-brane configurations, culminating in a Pati-Salam model with no open-string moduli.

Contribution

It provides a unified classification of shift Z2 x Z2 orientifolds and constructs fractional D-branes, including a realistic Pati-Salam model with stabilized moduli.

Findings

Shifts determine orbifold topology and orientifold plane presence.

A basis of homological three cycles is constructed.

A Pati-Salam model with no open-string moduli is achieved.

Abstract

We investigate Z2 x Z2 orientifolds with group actions involving shifts. A complete classification of possible geometries is presented where also previous work by other authors is included in a unified framework from an intersecting D-brane perspective. In particular, we show that the additional shifts not only determine the topology of the orbifold but also independently the presence of orientifold planes. In the second part, we work out in detail a basis of homological three cycles on shift Z2 x Z2 orientifolds and construct all possible fractional D-branes including rigid ones. A Pati-Salam type model with no open-string moduli in the visible sector is presented.