54 citations · 58 across the 3 of their papers we have counts for
6 papers · 1 filter
The Ponzano-Regge model and Reidemeister torsion
John W. Barrett, Ileana Naish-Guzman
The Ponzano-Regge model of three-dimensional quantum gravity is well-defined when the observables satisfy a certain condition involving the twisted cohomology. In this case, the pa…
Refractive gravitational waves and quantum fluctuations
John W. Barrett
Refractive gravitational waves are a generalisation of impulsive waves on a null hypersurface in which the metric is discontinuous but a weaker continuity condition for areas holds…
State sum models for quantum gravity
John W. Barrett
This paper reviews the construction of quantum field theory on a 4-dimensional spacetime by combinatorial methods, and discusses the recent developments in the direction of a combi…
The Quantum Tetrahedron in 3 and 4 Dimensions
John C. Baez, John W. Barrett
Recent work on state sum models of quantum gravity in 3 and 4 dimensions has led to interest in the `quantum tetrahedron'. Starting with a classical phase space whose points corres…
The asymptotics of an amplitude for the 4-simplex
John W. Barrett, Ruth M. Williams
An expression for the oscillatory part of an asymptotic formula for the relativistic spin network amplitude for a 4-simplex is given. The amplitude depends on specified areas for e…
Sources of symmetric potentials
John W. Barrett
Laboratory experiments on gravitation are usually performed with objects of constant density, so that the analysis of the forces concerns only the geometry of their shape. In an id…