Linking the Baum-Hawking-Coleman Mechanism with Unimodular Gravity and Vilenkin's Probability Flux

Abstract

We revisit a mechanism proposed by Hawking to resolve the cosmological constant problem (and the controversy it generated) to identify possibly more palatable alternatives and explore new connections and interpretations. In particular, through the introduction of a new action coupling the four-form field strength $F=dA$ to the cosmological constant via a dynamical field $\lambda (x)$, a novel Baum-Hawking-Coleman type mechanism is presented. This mechanism can be seen as a generalisation of Unimodular Gravity. A theory with a similar coupling to "$F^2$" is also presented, with promising results. We show how in such theories the 3-form is closely related to the Chern-Simons density, and its associated definition of time. On the interpretational front, we propose a method avoiding the standard Euclidean action prescription, which makes use of Vilenkin's probability flux.

7 pages

References in corpus (9)

• TASI Lectures on the Cosmological Constant
• Singularity resolution depends on the clock
• The Cosmological Constant is Probably Zero, and a Proof is Possibly Right
• Cosmological time and the constants of nature
• Parity violating Friedmann Universes
• Superconducting loop quantum gravity and the cosmological constant
• Quantum gravity as a Fermi liquid
• The real Chern-Simons wave function
• Quantum cosmology of a dynamical Lambda

Cited by in corpus (1)

• Probing Dark Energy Properties in $fQ,C)$ Gravity with FLRW Cosmological Models