Fundamental Aspects of Statistical Physics and Thermodynamics
Date: 27 - 30 March 2017
Convenors: Peter Reimann (Bielefeld, GER), Andreas Engel (Oldenburg, GER), Jochen Gemmer (Osnabrück, GER)
The main focus of this workshop was on the question of how the characteristic dynamical and statistical properties of macroscopically large as well as relatively
small systems can be deduced and understood from first principles, i.e., directly from the basic microscopic laws of physics. Within this broad and over 100 year old research area, the main emphasis was put on two topics of particular current interest, namely on the issue of whether and how isolated many-body systems approach thermal equilibrium, and on the adequate description and dedicated exploration of random fluctuations in small (sub-)systems under various externally imposed non-equilibrium conditions.
On the one hand, many-particle systems generically exhibit a so-called chaotic dynamics: their temporal evolution is in principle deterministic but in practice essentially unpredictable. On the other hand, they often obey some relatively simple ?phenomenological laws?, whose connection with the fundamental laws are, however, not very well understood. This antinomy is particularly pressing within the realm of nonequilibrium physics, one of the most fascinating open fields in fundamental science: The universal and irreversible tendency of closed nonequilibrium systems towards thermal equilibrium is a well-established empirical fact in the macroscopic world, but in spite of more than a century of theoretical efforts, it has still not been satisfactorily reconciled with the basic laws of physics, which govern the microscopic world, and which are fundamentally reversible.
In recent years, the joint efforts of practitioners from several disciplines have lead to promising new concepts for dealing with such fundamental questions regarding the dynamics of many-body systems far from equilibrium. The objective of the workshop was to bring together leading experts with complementary views on those questions from a variety of different disciplines, such as statistical physics, mathematical stochastics, numerical computing, or quantum information theory.
The workshop predominantly focused on two current research areas:
- Equilibration, thermalization, and relaxation times: The relaxation of isolated systems towards thermal equilibrium entails some very challenging questions: Why are the macroscopic phenomena reproducible even though the microscopic details are irreproducible and largely unknown in any real experiment? Why do such systems equilibrate in the first place, i.e., why do macroscopic observables approach certain stationary values for large times? Why do they thermalize, i.e., why are those stationary long time properties in agreement with the predictions of equilibrium statistical mechanics?
- Stochastic thermodynamics, fluctuation theorems, thermal and molecular machines: Crucial aspects of the physics far from equilibrium become particularly apparent in the analysis of small systems since their thermodynamic quantities are strongly fluctuating and thus the full probability distributions are necessary to characterize the system's behavior. New theoretical insights into the thermodynamics of small and fluctuating systems, now subsumed under the notion of stochastic thermodynamics, produced new laws for systems driven arbitrarily far from equilibrium, gave an unexpectedly fresh look on the statistical nature of the second law of thermodynamics, and revived the discussion about the interplay between statistical physics and information theory.