Prospects of Inflation

TL;DR

The paper surveys inflation's development and current status, emphasizing observational tests (e.g., $Ω_{tot}≈1$ and $n≈1$) and the drive to realize inflation within supergravity and string theory. It covers chaotic and hybrid inflation as concrete mechanisms, the generation of density perturbations via quantum fluctuations, and the concept of eternal inflation. It then reviews string-theoretic progress, including moduli stabilization via KKLT and the emergence of de Sitter vacua, brane inflation, and shift-symmetric constructions to tame the η-problem. The landscape of vacua suggests a multiverse with regions realizing different low-energy physics, while the interplay of eternal and slow-roll inflation offers a framework for understanding initial conditions and observable predictions.

Abstract

I will discuss the development of inflationary theory and its present status, including recent progress in describing de Sitter space and inflationary universe in string theory.