• Publications
  • Influence
Some properties of the Noether charge and a proposal for dynamical black hole entropy.
  • Iyer, Wald
  • Mathematics
    Physical review. D, Particles and fields
  • 15 March 1994
TLDR
It is proved that the first law of black hole mechanics holds for arbitrary perturbations of a stationary black hole, and a local, geometrical prescription is proposed for the entropy, $S_{dyn}$, of a dynamical black hole.
Black hole entropy is Noether charge.
  • Wald
  • Mathematics
    Physical review. D, Particles and fields
  • 29 July 1993
TLDR
The results show that the validity of the "second law" of black hole mechanics in dynamical evolution from an initially stationary black hole to a final stationary state is equivalent to the positivity of a total Noether flux, and thus may be intimately related to the positive energy properties of the theory.
Comparison of the Noether charge and Euclidean methods for computing the entropy of stationary black holes.
  • Iyer, Wald
  • Mathematics
    Physical review. D, Particles and fields
  • 27 March 1995
TLDR
In the course of the analysis, the definition of the Brown-York quasilocal energy is generalized to a much more general class of diffeomorphism invariant, Lagrangian theories of gravity.
Extrema of mass, stationarity, and staticity, and solutions to the Einstein-Yang-Mills equations.
  • Sudarsky, Wald
  • Mathematics
    Physical review. D, Particles and fields
  • 15 August 1992
TLDR
A generalization of the argument to the case in which an interior boundary is present proves that a necessary condition for a solution of the Einstein-Yang-Mills equation to be an extremum of mass at fixed area of the boundary surface is that the solution be static.
Does back reaction enforce the averaged null energy condition in semiclassical gravity?
  • Flanagan, Wald
  • Physics
    Physical review. D, Particles and fields
  • 27 February 1996
TLDR
It is suggested that if traversable wormholes do exist as solutions to the semiclassical equations, they cannot be macroscopic but must be ``Planck scale'', in agreement with conclusions drawn by Ford and Roman from entirely independent arguments.
Time and the interpretation of canonical quantum gravity.
  • Unruh, Wald
  • Physics
    Physical review. D, Particles and fields
  • 15 October 1989
TLDR
It is argued that the interpretive problems of quantum gravity are not alleviated by the incorporation of observers into the theory, and a proposal for a formulation of canonical quantum gravity in which an appropriate nondynamical time parameter is present is made.
Spin-two fields and general covariance.
  • Wald
  • Mathematics
    Physical review. D, Particles and fields
  • 15 June 1986
TLDR
The main result is the demonstration that only a very restricted class of candidate infinitesimal gauge symmetries can actually arise from an exact (i.e., finite) gauge symmetry, as is necessary to realize the theory.
Mass formulas for stationary Einstein-Yang-Mills black holes and a simple proof of two staticity theorems.
  • Sudarsky, Wald
  • Physics
    Physical review. D, Particles and fields
  • 25 May 1993
TLDR
A formula for JΩ-QV is derived, from which it follows immediately that any stationary, nonrotating, uncharged black hole is static and has a vanishing electric field on the static slices.
Evolution laws taking pure states to mixed states in quantum field theory.
  • Unruh, Wald
  • Physics
    Physical review. D, Particles and fields
  • 3 March 1995
TLDR
It is argued (via consideration of other, non-Markovian models) that conservation of energy and momentum for all states is not fundamentally incompatible with causality in dynamical models in which pure states evolve to mixed states.
Electron-optical-phonon interactions in ultrathin GaAs/AlAs multiple quantum wells.
TLDR
The data disagree with the macroscopic model of electron-phonon interaction, but they are in excellent agreement with the microscopic model proposed recently by Huang and Zhu.
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