PICS Colloquium: A geometric model for superfluid helium-4 with Michal Pavelka

Abstract: Superfluid helium is a peculiar liquid. For instance, it stays liquid even at very low temperatures (below 2K), it flows through narrow capillaries without friction, and temperature gradient makes it move even in the absence of pressure gradient. The usual description of superfluid helium-4 relies on the concept of two fluids, a so called normal component and a superfluid component, where the latter is responsible for the non-classical behavior. However, helium does not consist of two kinds of atoms and the two components can not be separated, so it does not really contain two fluids. Another approach towards the modelling of superfluid helium-4 is possible, where helium-4 is treated as only one fluid. The model is formulated within the GENERIC framework, combining Hamiltonian mechanics with gradient dynamics. The model is based on the correspondence principle between quantum commutators and Poisson brackets, and it goes beyond the usual models of superfluid helium-4.

Bio: Michal Pavelka is an associate professor of mathematical modeling at Charles University (Czech Republic). His research is focused on geometric non-equilibrium thermodynamics with applications in continuum physics, electrochemistry, numerical methods, and machine learning. He was a postdoc at École Polytechnique de Montréal, Canada, working with Miroslav Grmela, with whom he wrote a monograph Multiscale Thermo-Dynamics: Introduction to GENERIC.