Chaotic inflation and supersymmetry breaking

TL;DR

The paper extends chaotic inflation in supergravity by coupling the inflaton sector to KL-based moduli stabilization and SUSY breaking, addressing the cosmological moduli and gravitino problems. It shows that a heavy volume modulus can stabilize during inflation and decouple from the inflaton dynamics, preserving chaotic inflation with arbitrary potentials, while uplifting yields low-scale SUSY breaking without Polonyi-type moduli. Reheating proceeds through gauge-kinetic couplings, yielding a suppressed reheating temperature that alleviates gravitino constraints. The result is a versatile, string-inspired framework for chaotic inflation compatible with low-energy SUSY and robust moduli stabilization.

Abstract

We investigate the recently proposed class of chaotic inflation models in supergravity with an arbitrary inflaton potential. These models are extended to include matter fields in the visible sector and we employ a mechanism of SUSY breaking based on a particular phenomenological version of the KKLT mechanism (the KL model). We describe specific features of reheating in this class of models and show how one can solve the cosmological moduli and gravitino problems in this context.

Figures (2)

• Figure 1: Scalar potential of the KL model for the values of the parameters $A=B =1$, $a = \pi/25$, $b = \pi/10$ as a function of the canonically normalized volume modulus field $\sqrt{3/2} \ln \sigma$.
• Figure 2: The first of these plots shows the potential with the parameters in (\ref{['eqn:paramset']}) as a function of $\phi$ and $\sigma$. The Kähler potential has $K_{S\bar{S} S\bar{S}}=0$ (no stabilization of $s$, as in Davis:2008fv). For each value of $\phi$ and $\sigma$, $s$ is adjusted so that the potential is minimized. The red line shows the inflaton trajectory. Inflation is possible for $|\phi|< 140$; further increase of $\phi$ destabilizes the potential. The second plot corresponds to the situation where we stabilize $s$ near $s = 0$ by taking $K_{S\bar{S} S\bar{S}}=-4$. We increase $A$ and $B$ by a factor of 5, to increase the height of the barrier. In this regime inflation is possible for $\phi$ well above 1000, in Planck units. In the investigation of the observational consequences of inflation in this regime one can ignore the KL potential and use the results of the previous investigation of chaotic inflation in supergravity Kallosh:2010ugKallosh:2010xz.