Remarks on M Theoretic Cosmology

TL;DR

This paper discusses a cosmological model inspired by Horava-Witten theory, linking unification, SUSY breaking, and dark matter to fundamental scales and boundary moduli, with implications for early universe dynamics and observable cosmological parameters.

Contribution

It proposes a cosmological framework where boundary moduli explain dark matter and connects fundamental scales to observable universe features, integrating SUSY breaking and inflation.

Findings

Unification scale near the fundamental gravitational scale.

Dark matter as a boundary modulus, possibly the QCD axion.

The ratio of fundamental to effective Planck scales influences cosmic microwave background fluctuations.

Abstract

I present cosmological arguments which point towards a Horava-Witten like picture of the universe, with the unification scale of order the fundamental gravitational scale. The SUSY breaking scale is determined by the dynamics of gauge fields which are weakly coupled at the fundamental scale. Bulk moduli whose potential originates at short distances are the inflatons, while bulk moduli whose potential originates from SUSY breaking are the origin of the energy density in the present era. The latter decay just before nucleosynthesis, and a consistent theory of baryogenesis requires that there be renormalizable baryon number violating interactions at the TeV scale. The dark matter is a boundary modulus, perhaps the QCD axion, and the temperature of matter radiation equality is related to the ratio between the fundamental and effective four dimensional Planck scales. The same ratio determines the amplitude of fluctuations in the microwave background.