Quantum back-reaction of the superpartners in a large-N supersymmetric hybrid model

TL;DR

This paper investigates the quantum backreaction effects of superpartners in a large-N supersymmetric hybrid inflation model, revealing slow waterfall field evolution and the significance of pseudoscalar fluctuations in late-time dynamics.

Contribution

It introduces a large-N approximation to account for superpartner backreaction in supersymmetric hybrid inflation, highlighting the impact on post-inflation dynamics.

Findings

Fluctuations of the pseudoscalar superpartner are crucial in late-time behavior.

Waterfall field evolution is slow, indicating a flat potential and stochastic influences.

Two distinct phases in the evolution after slow roll are identified.

Abstract

We study the supersymmetric hybrid model near and after the end of inflation. As usual, we reduce the model to a purely scalar hybrid model on the level of the classical fields. But on the level of quantum fluctuations and their backreaction we take into account all superpartners of the waterfall field in a large-N approximation. The evolution after slow roll displays two phases with a different characteristic behaviour of the classical and fluctuation fields. We find that the fluctuations of the pseudoscalar superpartner are of particular importance in the late time phase. The motion of the waterfall field towards its classical expectation value is found to be very slow and suggests a rather flat potential and a stochastic force.