Dark Energy From The Gravity Vacuum

Abstract

We propose a new solution to the cosmological constant problem building on a nonperturbative quantum theory of gravity with torsional instantons. These pseudoparticles, which were recently found to exist in a first order formulation of Giddings-Strominger axionic gravity, carry nontrivial Nieh-Yan topological charge. The nonperturbative ground state as generated due to tunneling effects is shown to be stable under quantum fluctuations. Within this framework, the associated vacuum angle, namely the Barbero-Immirzi topological parameter, gets fixed to a numerical value determined by the Hubble constant.

Matches the version to be published in Class. Quantum Grav.; Title changed

References in corpus (6)

• Dynamics of dark energy
• Everything You Always Wanted To Know About The Cosmological Constant Problem (But Were Afraid To Ask)
• Topological Interpretation of Barbero-Immirzi Parameter
• Cosmological Constant from the Emergent Gravity Perspective
• Gravity Asymptotics with Topological Parameters
• Torsional instanton effects in quantum gravity

Cited by in corpus (1)

• Understanding General Relativity after 100 years: A matter of perspective