An algebraic approach to the derivation of effective macroscopic evolution equations

forthcoming

Physical systems can be approached at microscopic and macroscopic levels. The former are described in terms of elementary constituents and fundamental interactions, e.g., Newton's theory of classical mechanics, Schrödinger's equation in quantum mechanics and Einstein's general theory of relativity. Although a microscopic description is often very accurate, it is usually not well suited for calculations because of the large number of degrees of freedom. On the other hand, a macroscopic description of the system takes into account only effective interactions, which arise from the collective behaviour of the system and are of interest to the `observer'. Such a description is less accurate, but much more accessible for calculations. Because of the great importance of effective macroscopic theories for making qualitative and quantitative predictions about the behaviour of physical systems, a major goal of statistical mechanics is to understand their emergence from microscopic theories. In this project, we propose a novel approach that generalizes the derivation of macroscopic evolution equations. The overarching main scientific objective of this project is: to develop a mathematical framework based on resolvent algebras in which effective macroscopic evolution equations can be rigorously derived. Despite the fact that many theoretical studies have been devoted to this derivation, most results are based on ad-hoc methods. This project generalizes these by introducing an algebraic setting based on resolvent algebras. These algebras have both a classical and quantum counterpart and form an excellent setting to study many-body interacting systems. Although resolvent algebras have already proved successful in other studies, the new challenge is to exploit their structure to derive effective macroscopic evolution equations.