k-Inflation

TL;DR

k-inflation demonstrates that a broad class of higher-order scalar kinetic terms can independently drive inflation from generic initial conditions, providing a potential new approach to reconcile string theory with cosmological inflation.

Contribution

This paper introduces kinetically driven inflation (k-inflation), a novel mechanism where non-quadratic kinetic terms alone can cause inflation without potential terms.

Findings

Can start from high-curvature initial conditions

Naturally transitions to radiation-dominated phase

Provides a new perspective on string dilaton and inflation

Abstract

It is shown that a large class of higher-order (i.e. non-quadratic) scalar kinetic terms can, without the help of potential terms, drive an inflationary evolution starting from rather generic initial conditions. In many models, this kinetically driven inflation (or "k-inflation" for short) rolls slowly from a high-curvature initial phase, down to a low-curvature phase and can exit inflation to end up being radiation-dominated, in a naturally graceful manner. We hope that this novel inflation mechanism might be useful in suggesting new ways of reconciling the string dilaton with inflation.