Cosmological Moduli Problem in Low Cutoff Theory

TL;DR

This paper demonstrates that lowering the universal cutoff scale below the Planck scale can resolve the cosmological moduli problem without requiring large entropy production, allowing for high reheating temperatures compatible with non-thermal leptogenesis.

Contribution

It introduces a new approach to solving the cosmological moduli problem by considering a lower cutoff scale, providing a general estimate of modulus abundance related to inflation and reheating.

Findings

Cosmological moduli problem can be solved with a lower cutoff scale.

Reheating temperature can be sufficiently high for non-thermal leptogenesis.

A general estimate of modulus abundance in terms of inflation and reheating is provided.

Abstract

We show that the cosmological moduli problem is solved, without relying on huge late-time entropy production, if the universal cutoff scale of the theory is a few orders of magnitude smaller than the Planck scale. We obtain a general estimate of the modulus abundance in terms of the inflationary scale and the reheating temperature, and find in particular that the reheating temperature can be high enough for the non-thermal leptogenesis to work.