A simple model for quintessential inflation

Abstract

We propose a simple toy model for quintessential inflationwhere a complex scalar field described by a Lagrangian with aU(1)PQ symmetry spontaneously broken at a high energy scale and explicitly broken by instantoneffects at a much lower energy can account for both the early inflationary phase and therecent accelerated expansion of the Universe. The real part of the complex field plays therole of the inflaton whereas the imaginary part, the ‘axion’, is the quintessence field.