Successfully combining SUGRA hybrid inflation and moduli stabilization

Inflation and moduli stabilization mechanisms work well independently, and many string-motivated supergravity models have been proposed for them. However, a complete theory will contain both, and there will be (gravitational) interactions between the two sectors. These give corrections to the inflaton potential, which generically ruin inflation. This holds true even for fine-tuned moduli stabilization schemes. Following a suggestion by Achucarro and Sousa (2007 Preprint 0712.3460), we show that a viable combined model can be obtained if it is the Kahler functions (G = K+ ln vertical bar W vertical bar(2)) of the two sectors that are added, rather than the superpotentials (as is usually done). Interaction between the two sectors does still impose some restrictions on the moduli stabilization mechanism, which are derived. Significantly, we find that the (post-inflation) moduli stabilization scale no longer needs to be above the inflationary energy scale.