Uplifting and Inflation with D3 Branes

TL;DR

This paper investigates how back-reaction effects influence D3 brane dynamics in type IIB string theory, affecting inflationary models, potential uplifting mechanisms, and the role of D-term forces in supergravity frameworks.

Contribution

It provides a calculable analysis of back-reaction effects on D3 branes, explores alternative uplifting methods without anti-D3 branes, and clarifies the role of D-term forces in D3/D7 inflation scenarios.

Findings

Back-reaction effects can modify or preserve slow-roll conditions depending on brane trajectories.

A new mechanism for uplifting vacua without anti-D3 branes is proposed.

D-term forces and supergravity interactions are characterized in D3/D7 inflation models.

Abstract

Back-reaction effects can modify the dynamics of mobile D3 branes moving within type IIB vacua, in a way which has recently become calculable. We identify some of the ways these effects can alter inflationary scenarios, with the following three results: (1) By examining how the forces on the brane due to moduli-stabilizing interactions modify the angular motion of D3 branes moving in Klebanov-Strassler type throats, we show how previous slow-roll analyses can remain unchanged for some brane trajectories, while being modified for other trajectories. These forces cause the D3 brane to sink to the bottom of the throat except in a narrow region close to the D7 brane, and do not ameliorate the \eta-problem of slow roll inflation in these throats; (2) We argue that a recently-proposed back-reaction on the dilaton field can be used to provide an alternative way of uplifting these compactifications to Minkowski or De Sitter vacua, without the need for a supersymmetry-breaking anti-D3 brane; and (3) by including also the D-term forces which arise when supersymmetry-breaking fluxes are included on D7 branes we identify the 4D supergravity interactions which capture the dynamics of D3 motion in D3/D7 inflationary scenarios. The form of these potentials sheds some light on recent discussions of how symmetries constrain D term interactions in the low-energy theory.