D3-brane vacua in stabilized compactifications

Abstract

D3-branes feel no force in no-scale flux compactifications of type IIB string theory, but the nonperturbative effects required to stabilize the Kähler moduli break the no-scale structure and generate a potential for D3-brane motion, confining the branes to certain loci. D3-branes away from these loci break supersymmetry spontaneously, by an F-term. We present the general conditions for supersymmetric D3-brane vacua in models with a single Kähler modulus, then explicitly calculate these vacua for D3-branes moving on the tip of the warped deformed conifold. We find both continuous moduli spaces and isolated vacua. In addition, we show that 3-branes and D3-branes are localized to the same regions by the nonperturbative potential, avoiding a potential obstacle to brane inflation. We apply these results to determine whether angular motion of a brane in a throat could play an important role in inflation, and find that any inflation along the angular directions is short-lived because the field space is very small. © SISSA 2007.