Loop Quantum Cosmology Gravitational Baryogenesis

TL;DR

This paper explores how Loop Quantum Cosmology modifies gravitational baryogenesis, leading to a non-zero baryon-to-entropy ratio even during radiation domination, contrasting with classical predictions.

Contribution

It demonstrates that Loop Quantum Cosmology effects result in a non-zero baryon-to-entropy ratio in radiation-dominated universes, unlike classical Einstein-Hilbert gravity.

Findings

Non-zero baryon-to-entropy ratio in LQC during radiation era

Dependence of baryon asymmetry on quantum parameters

Compatibility of LQC solutions with observational constraints

Abstract

Loop Quantum Cosmology is an appealing quantum completion of classical cosmology, which brings along various theoretical features which in many cases offer remedy or modify various classical cosmology aspects. In this paper we address the gravitational baryogenesis mechanism in the context of Loop Quantum Cosmology. As we demonstrate, when Loop Quantum Cosmology effects are taken into account in the resulting Friedmann equations for a flat Friedmann-Robertson-Walker Universe, then even for a radiation dominated Universe, the predicted baryon-to-entropy ratio from the gravitational baryogenesis mechanism is non-zero, in contrast to the Einstein-Hilbert case, in which case the baryon-to-entropy ratio is zero. We also discuss various other cases apart from the radiation domination case, and we discuss how the baryon-to-entropy ratio is affected from the parameters of the quantum theory. In addition, we use illustrative exact solutions of Loop Quantum Cosmology and we investigate under which circumstances the baryon-to-entropy ratio can be compatible with the observational constraints.