4 papers
Bianchi - Euler system for relativistice fluids and Bel - Robinson type energy
Yvonne Choquet-Bruhat, James W. York
We write a first order symmetric hyperbolic system coupling the Riemann with the dynamical acceleration of a relativistic fluid. W determine the associated, coupled, Bel - Robinson…
On H. Friedrich's formulation of Einstein'equations with fluid sources
Yvonne Choquet-Bruhat, James W. York
We establish a variant, which has the advantage of introducing only physical characteristics, of the symmetric quasi linear first order system given by H.\ Friedrich for the evolut…
Constraints and evolution in cosmology
Yvonne Choquet-Bruhat, James W. York
We review some old and new results about strict and non strict hyperbolic formulations of the Einstein equations.
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…