Fourdimensional spinfoam quantum gravity with a cosmological constant: Finiteness and semiclassical limit
Abstract
We present an improved formulation of 4dimensional Lorentzian spinfoam quantum gravity with a cosmological constant. The construction of spinfoam amplitudes uses the stateintegral model of PSL (2 ,C ) ChernSimons theory and the implementation of a simplicity constraint. The formulation has two key features: (1) spinfoam amplitudes are all finite, and (2) with suitable boundary data, the semiclassical asymptotics of the vertex amplitude has two oscillatory terms, with phase plus or minus the 4dimensional Lorentzian Regge action with a cosmological constant for the constant curvature 4simplex.
 Publication:

Physical Review D
 Pub Date:
 November 2021
 DOI:
 10.1103/PhysRevD.104.104035
 arXiv:
 arXiv:2109.00034
 Bibcode:
 2021PhRvD.104j4035H
 Keywords:

 General Relativity and Quantum Cosmology;
 High Energy Physics  Theory;
 Mathematics  Geometric Topology
 EPrint:
 25 pages, 8 figures