Dilaton tadpoles and D-brane interactions in compact spaces

TL;DR

This paper investigates the effects of supersymmetry breaking by D-branes and orientifold planes in Type II string theories, focusing on dilaton tadpoles, their physical consequences, and how to achieve finite D-brane interactions in compact spaces.

Contribution

It provides a detailed analysis of global dilaton tadpoles in compact spaces and explores mechanisms to obtain finite D-brane and orientifold interactions at the supergravity level.

Findings

Global dilaton tadpoles appear at disk level in compact spaces.

Non-cancelled tadpoles lead to a constant term solving equations of motion.

Broken Poincaré invariance in non-compact directions can be modeled cosmologically.

Abstract

We analyse some physical consequences when supersymmetry is broken by a set of D-branes and/or orientifold planes in Type II string theories. Generically, there are global dilaton tadpoles at the disk level when the transverse space is compact. By taking the toy model of a set of electric charges in a compact space, we discuss two different effects appearing when global tadpoles are not cancelled. On the compact directions a constant term appears that allows to solve the equations of motion. On the non-compact directions Poincar\'e invariance is broken. We analyse some examples where the Poincar\'e invariance is broken along the time direction (cosmological models).After that, we discuss how to obtain a finite interaction between D-branes and orientifold planes in the compact space at the supergravity level.