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Stephen P. Braham

Publications and source records attributed to Stephen P. Braham.

3 recordsLinked to original sources

Hypertime Formalism for Spherically Symmetric Black Holes and Wormholes

Recent work on an approach to the geometrodynamics of cylindrical gravity waves in the presence of interacting scalar matter fields, based on the Kuchař hypertime formalism, is extended to the analogous spherically symmetric system. This produces a geometrodynamical formalism for spherical black holes and wormholes in which the metric variables are divided into two classes, dynamical and redundant. The redundant variables measure the embedding of a spacelike hypersurface into the spacetime, and proper time in the asymptotically flat regions. All the constraints can be explicitly solved for the momenta conjugate to the embedding variables. The dynamical variables, including an extra ADM mass for wormhole topologies, can then be considered as functionals of the redundant ones, including the proper time variable. The solution of the resulting constraint system determines the momentum conjugate to the proper time as a function of the other variables, producing Unruh's Hamiltonian formalism for the spherical black hole, whilst extending it to an arbitrary foliation choice. The resulting formalism is appropriate as a starting point for the construction of a hypertime functional Schrödinger equation for quantized spherically symmetric black holes and wormholes.

gr-qc

A Kuchař Hypertime Formalism For Cylindrically Symmetric Spacetimes With Interacting Scalar Fields

The Kuchař canonical transformation for vacuum geometrodynamics in the presence of cylindrical symmetry is applied to a general non-vacuum case. The resulting constraints are highly non-linear and non-local in the momenta conjugate to the Kuchař embedding variables. However, it is demonstrated that the constraints can be solved for these momenta and thus the dynamics of cylindrically symmetric models can be cast in a form suitable for the construction of a hypertime functional Schrödinger equation.

gr-qc

Generalized embedding variables for geometrodynamics and spacetime diffeomorphisms: Ultralocal coordinate conditions

We investigate the embedding variable approach to geometrodynamics advocated in work by Isham, Kuchař and Unruh for a general class of coordinate conditions that mirror the Isham-Kuchař Gaussian condition but allow for arbitrary algebraic complexity. We find that the same essential structure present in the ultralocal Gaussian condition is repeated in the general case. The resultant embedding--extended phase space contains a full representation of the Lie algebra of the spacetime diffeomorphism group as well as a consistent pure gravity sector.

hep-th