Higgs, Moduli Problem, Baryogenesis and Large Volume Compactifications

TL;DR

This paper explores how the LARGE volume scenario in string theory can address the cosmological moduli and gravitino problems while enabling baryogenesis via the Affleck-Dine mechanism, and discusses implications for dark radiation.

Contribution

It demonstrates that the LARGE volume scenario can solve the moduli and gravitino problems and facilitate baryogenesis through the Affleck-Dine mechanism, including effects of Q-balls and axionic dark radiation.

Findings

Moduli decay into axionic superpartners, contributing to dark radiation.

Affleck-Dine baryogenesis is viable in the LARGE volume scenario.

The scenario avoids the gravitino overproduction problem.

Abstract

We consider the cosmological moduli problem in the context of high-scale supersymmetry breaking suggested by the recent discovery of the standard-model like Higgs boson. In order to solve the notorious moduli-induced gravitino problem, we focus on the LARGE volume scenario, in which the modulus decay into gravitinos can be kinematically forbidden. We then consider the Affleck-Dine mechanism with or without an enhanced coupling with the inflaton, taking account of possible Q-ball formation. We show that the baryon asymmetry of the present Universe can be generated by the Affleck-Dine mechanism in LARGE volume scenario, solving the moduli and gravitino problems. We also find that the overall volume modulus decays into a pair of the axionic superpartners, which contribute to the extra relativistic degrees of freedom.