More varieties of hybrid inflation

Abstract

It is pointed out that hybrid inflation can be implemented with the inflaton field rolling away from the origin instead of towards it. This `inverted' hybrid inflation has a spectral index $n<1$, in contrast with ordinary hybrid inflation which has $n\gtrsim 1$, so a measured value of $n$ substantially different from 1 would distinguish the two. Other generalisations of hybrid inflation are also considered.

Comments: 9 pages