Axion monodromy inflation and the late time universe

Abstract

In this paper we analyse the viability of a solution for early and late time evolution of the universe. The standard model of cosmology, the Λ𝐶𝐷𝑀 model, contains subtle inconsistencies with the nature of the Cosmic Microwave Background radiation. To alleviate these problems cosmic inflation of some form is required to explain early universe evolution. In this paper, we focus on a large-field inflationary model called axion monodromy inflation (AMI). Large-field models require a UV-complete to fully explain the high-energy physical phenomena. We opt to use superstring theory as the UV-complete theory. This means that we must construct a de Sitter minimum for the universe at late time from superstring theory, for which we choose the Kachru Kallosh Linde Trivedi (KKLT) mechanism. We analyse the consequences of taking these two mechanisms together and conclude that a naïve integration of the two models is not consistent, leading to an 𝜂-problem in the axion monodromy model.