In the frame of the theory of subdynamics a general picture of the time evolution of a many-body system has been developed by the Brussels school of statistical mechanics. In this paper, we avoid the perturbation scheme so that we get compact notations and demonstrations. We derive here a general expression for the commutator of an arbitrary superoperator W with the " asymptotic " evolution superoperator Σ(t) = ΠU(t) where [formula] is the complete evolution superoperator and where Π is the usual superprojector of the theory of subdynamics. In the frame of relativistic non-equilibrium statistical mechanics, the application of this commutator to all the generators of the Poincaré group is then given and we get back in particular the fundamental property of commutation with Π of the Lorentz-Liouville superoperator.In the frame of the theory of subdynamics a general picture of the time evolution of a many-body system has been developed by the Brussels school of statistical mechanics. In this paper, we avoid the perturbation scheme so that we get compact notations and demonstrations. We derive here a general expression for the commutator of an arbitrary superoperator W with the " asymptotic " evolution superoperator Σ(t) = ΠU(t) where [formula] is the complete evolution superoperator and where Π is the usual superprojector of the theory of subdynamics. In the frame of relativistic non-equilibrium statistical mechanics, the application of this commutator to all the generators of the Poincaré group is then given and we get back in particular the fundamental property of commutation with Π of the Lorentz-Liouville superoperator.

Bulletin de la Classe des sciencesJan 1, 19790 citations

Global Observables in Statistical Mechanics

Christiaan J. F. van de Ven

Abstract We present a canonical construction of global observables -sometimes referred to in the literature as macroscopic observables or observables at infinity- in statistical mechanics, providing a unified treatment of both commutative and non-commutative cases. Unlike standard approaches, the framework is formulated directly in the $C^*$ C ∗ -algebraic setting, without relying on any specific representation.Abstract We present a canonical construction of global observables -sometimes referred to in the literature as macroscopic observables or observables at infinity- in statistical mechanics, providing a unified treatment of both commutative and non-commutative cases. Unlike standard approaches, the framework is formulated directly in the $$C^*$$ C ∗ -algebraic setting, without relying on any specific representation.

arXiv:2510.26736International Journal of Theoretical PhysicsJul 31, 20260 citations

C^*

C ∗ -algebraic setting, without relying on any specific representation.