Cosmology and the Fate of Dilatation Symmetry

Understand

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.