The Chaotic Regime of D-Term Inflation

TL;DR

This paper explores a D-term inflation model where a waterfall transition leads to a phase resembling chaotic inflation, showing how false vacuum decay can naturally end with standard inflationary predictions.

Contribution

It presents a detailed analysis of D-term inflation with small couplings, demonstrating how the waterfall transition results in a chaotic inflation-like phase.

Findings

Waterfall field becomes classical after quantum fluctuations.

Inflaton potential becomes quadratic during final inflation stage.

Model connects false vacuum decay to chaotic inflation predictions.

Abstract

We consider D-term inflation for small couplings of the inflaton to matter fields. Standard hybrid inflation then ends at a critical value of the inflaton field that exceeds the Planck mass. During the subsequent waterfall transition the inflaton continues its slow-roll motion, whereas the waterfall field rapidly grows by quantum fluctuations. Beyond the decoherence time, the waterfall field becomes classical and approaches a time-dependent minimum, which is determined by the value of the inflaton field and the self-interaction of the waterfall field. During the final stage of inflation, the effective inflaton potential is essentially quadratic, which leads to the standard predictions of chaotic inflation. The model illustrates how the decay of a false vacuum of GUT-scale energy density can end in a period of `chaotic inflation'.