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The cosmological constant as a boundary term
- Source :
- Journal of high energy physics 08(8), 167 (2022). doi:10.1007/JHEP08(2022)167, Journal of High Energy Physics
- Publication Year :
- 2022
- Publisher :
- Springer Science and Business Media LLC, 2022.
-
Abstract
- Journal of high energy physics 08(8), 167 (2022). doi:10.1007/JHEP08(2022)167<br />We compare the path integral for transition functions in unimodular gravity and in general relativity. In unimodular gravity the cosmological constant is a property of states that are specified at the boundaries whereas in general relativity the cosmological constant is a parameter of the action. Unimodular gravity with a nondynamical background spacetime volume element has a time variable that is canonically conjugate to the cosmological constant. Wave functions depend on time and satisfy a Schrödinger equation. On the contrary, in the covariant version of unimodular gravity with a 3-form gauge field, proposed by Henneaux and Teitelboim, wave functions are time independent and satisfy a Wheeler-DeWitt equation, as in general relativity. The 3-form gauge field integrated over spacelike hypersurfaces becomes a “cosmic time” only in the semiclassical approximation. In unimodular gravity the smallness of the observed cosmological constant has to be explained as a property of the initial state.<br />Published by SISSA, [Trieste]
- Subjects :
- High Energy Physics - Theory
wave function
Nuclear and High Energy Physics
background [space-time]
approximation: semiclassical
FOS: Physical sciences
General Relativity and Quantum Cosmology (gr-qc)
space-time: background
gravitation: unimodular
General Relativity and Quantum Cosmology
High Energy Physics::Theory
High Energy Physics - Phenomenology (hep-ph)
approximation, semiclassical
gravitation, unimodular
general relativity
Models of Quantum Gravity
ddc:530
initial state
cosmological constant
unimodular [gravitation]
Wheeler-DeWitt equation
boundary condition
High Energy Physics - Phenomenology
semiclassical [approximation]
High Energy Physics - Theory (hep-th)
covariance
gauge field theory
Schroedinger equation
space-time, background
Classical Theories of Gravity
path integral
Subjects
Details
- ISSN :
- 10298479
- Volume :
- 2022
- Database :
- OpenAIRE
- Journal :
- Journal of High Energy Physics
- Accession number :
- edsair.doi.dedup.....8bbc860803b1783f91fbb4a62733fa96
- Full Text :
- https://doi.org/10.3204/PUBDB-2022-01625