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- Publications
- Influence
Mass, luminosity, and line width relations of Galactic molecular clouds
- P. M. Solomon, A. R. Rivolo, J. Barrett, A. Yahil
- Physics
- 1 August 1987
The paper presents an analysis of the cloud sizes, velocity line widths, viral masses, and CO luminosities of 273 Galactic molecular clouds which utilizes the higher resolution Massachusetts-Stony… Expand
THE MOLECULAR INTERSTELLAR MEDIUM IN ULTRALUMINOUS INFRARED GALAXIES
- P. M. Solomon, D. Downes, S. Radford, J. Barrett
- Physics
- 21 October 1996
We present observations with the IRAM 30 m telescope of CO in a large sample of ultraluminous IR galaxies out to redshift z = 0.3. Most of the ultraluminous galaxies in this sample are interacting,… Expand
Temperley-Lieb Recoupling Theory and Invariants of 3-Manifolds
- J. Barrett
- Physics
- 5 July 1994
I used to keep the entire spin networks literature in a small folder on my shelf. The recent explosion of interest in the subject has made this impossible; more is probably now written every week… Expand
Relativistic spin networks and quantum gravity
- J. Barrett, L. Crane
- Physics
- 12 September 1997
Relativistic spin networks are defined by considering the spin covering of the group SO(4), SU(2)×SU(2). Relativistic quantum spins are related to the geometry of the two-dimensional faces of a… Expand
Lorentzian spin foam amplitudes: graphical calculus and asymptotics
- J. Barrett, R. Dowdall, W. Fairbairn, F. Hellmann, Roberto Pereira
- Physics, Mathematics
- 14 July 2009
The amplitude for the 4-simplex in a spin foam model for quantum gravity is defined using a graphical calculus for the unitary representations of the Lorentz group. The asymptotics of this amplitude… Expand
Finite element approximation of the p-Laplacian
- J. Barrett, W. Liu
- Mathematics
- 13 January 1993
In this paper we consider the continuous piecewise linear finite el- ement approximation of the following problem: Given p € (1, oo), /, and g , find u such that -V • (\Vu\"-2Vu) = f iniicR2, u = g… Expand
A Lorentzian signature model for quantum general relativity
- J. Barrett, L. Crane
- Physics
- 9 April 1999
We give a relativistic spin network model for quantum gravity based on the Lorentz group and its q-deformation, the Quantum Lorentz Algebra.
We propose a combinatorial model for the path integral… Expand
Spherical Categories
- J. Barrett, B. W. Westbury
- Physics, Mathematics
- 25 October 1993
This paper is a study of monoidal categories with duals where the tensor product need not be commutative. The motivating examples are categories of representations of Hopf algebras. We introduce the… Expand
Holonomy and path structures in general relativity and Yang-Mills theory
- J. Barrett
- Mathematics
- 1 September 1991
This article is about a different representation of the geometry of the gravitational field, one in which the paths of test bodies play a crucial role. The primary concept is the geometry of the… Expand
Invariants of piecewise-linear 3-manifolds
- J. Barrett, B. W. Westbury
- Physics, Mathematics
- 25 November 1993
In this paper we develop a theory for constructing an invariant of closed oriented 3-manifolds, given a certain type of Hopf algebra. Examples are given by a quantised enveloping algebra of a… Expand