M Theory and Cosmology

TL;DR

This work surveys how M-theory, via branes, moduli, and dualities, provides a cosmological framework for vacuum selection, quantum cosmology, and inflation. It argues that moduli fields act as natural clocks and inflatons, with dualities mapping cosmological singularities to smoother descriptions and with the Hořava–Witten setup offering a high-scale origin for inflationary dynamics, potentially yielding a density fluctuation amplitude consistent with observations. The analysis emphasizes wrapped branes, central charges, and enhanced gauge symmetries as key mechanisms shaping low-energy physics, while proposing inflationary and anti-inflationary scenarios within a unified M-theory context. It further explores the cosmological moduli problem, axion/dark-modulus dark matter ideas, and baryogenesis pathways, highlighting how the unification scale and Planck scale enter cosmological evolution. Overall, the framework suggests that moduli dynamics and brane physics in M-theory can naturally account for several cosmological observations and offer distinctive, testable predictions, such as high-scale inflationary signatures and nonstandard dark matter possibilities, all within the constraints of a highly supersymmetric, yet dynamically evolving, early universe.

Abstract

This is a series of lectures on M Theory for cosmologists. After summarizing some of the main properties of M Theory and its dualities I show how it can be used to address various fundamental and phenomenological issues in cosmology.