2021/07/03 by Ryuichi Nakayama, Nakayama, Ryuichi
Physics and Astronomy · #Black Holes and Theoretical Physics #Cosmology and Gravitation Theories #FOS: Physical sciences #High Energy Physics - Theory (hep-th) #Quantum Electrodynamics and Casimir Effect
paper · pdf · doi:10.48550/arxiv.2107.01371
openalex publication_date 2021/07/03 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
BRST-invariant action of general relativity in the unimodular gauge proposed by Baulieu is studied without using perturbative expansions. The expression for the path integral in the unimodular gauge is reduced to a form in which a functional measure is defined by a norm invariant under Transverse Diffeomorphism. It is shown that general relativity in the unimodular gauge with this action and the quantum unimodular gravity are equivalent. It is also shown that Vacuum Expectation Values (VEVs) of Diff invariant operators in the unimodular gauge and other gauge such as the harmonic gauge take distinct values. A path integral for harmonic gauge is found to be gauge equivalent to a superposition of that for unimodular gauge obtained by performing constant Weyl transformation of the metric, after a non-dynamical cosmological term is introduced into the action of the unimodular gauge.