5 papers · 1 filter
Einstein's Equations and Equivalent Hyperbolic Dynamical Systems
Arlen Anderson, Yvonne Choquet-Bruhat, James W. York
We discuss several explicitly causal hyperbolic formulations of Einstein's dynamical 3+1 equations in a coherent way, emphasizing throughout the fundamental role of the ``slicing f…
Generalized Einstein theory with fundamental cosmological stress tensor
Arlen Anderson
Careful analysis of parametrized variational principles in mechanics and field theory leads to a generalization of Einstein theory that includes a cosmological stress tensor. This…
Clocks and Time
Arlen Anderson
A general definition of a clock is proposed, and the role of clocks in establishing temporal pre-conditions in quantum mechanical questions is critically discussed. The different s…
Evolving Constants of Motion
Arlen Anderson
A critical presentation of Rovelli's ``evolving constants of motion'' is given. Previous criticisms by Kuchař concerning the role of factor ordering and the non-existence of observ…
Thawing the Frozen Formalism: The Difference Between Observables and What We Observe
Arlen Anderson
In a parametrized and constrained Hamiltonian system, an observable is an operator which commutes with all (first-class) constraints, including the super-Hamiltonian. The problem o…