Quantum Weyl Invariance and Cosmology

Understand

Equations for cosmological evolution are formulated in a Weyl invariant formalism to take into account possible Weyl anomalies.

• Near two dimensions, the renormalized cosmological term leads to a nonlocal energy-momentum tensor and a slowly decaying vacuum energy.
• A natural generalization to four dimensions implies a quantum modification of Einstein field equations at long distances.
• It offers a new perspective on time-dependence of couplings and naturalness with potentially far-reaching consequences for the cosmological constant problem, inflation, and dark energy.