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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

1,095 341

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

663 219- PDF

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

480 51

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

544 45- PDF

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

180 22- PDF

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

157 20- PDF

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

306 20- PDF

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

130 19- PDF

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

106 19

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

184 15- PDF