Cosmology and the Fate of Dilatation Symmetry

TL;DR

This paper explores how dilatation symmetry and its anomalies influence cosmological models, potentially addressing the cosmological constant problem and predicting deviations from standard cosmology.

Contribution

It links dilatation symmetry and its anomaly to cosmological evolution, proposing conditions for realistic asymptotic cosmology and observable deviations.

Findings

Dilatation symmetric theories can yield realistic cosmology with a non-trivial potential minimum.

Anomalies in dilatation symmetry require a specific vacuum energy condition related to the renormalization group.

Observable deviations from standard cosmology are possible due to dilatation symmetry considerations.

Abstract

We discuss the cosmological constant problem in the light of dilatation symmetry and its possible anomaly. For dilatation symmetric quantum theories realistic asymptotic cosmology is obtained provided the effective potential has a non-trivial minimum. For theories with dilatation anomaly one needs as a non-trivial "cosmon condition" that the energy-momentum tensor in the vacuum is purely anomalous. Such a condition is related to the short-distance renormalization group behavior of the fundamental theory. Observable deviations from the standard hot big bang cosmology are possible.