Speaker: Masaru Hongo (Illinois Univ.)

Date: Nov. 30th, 21:00 (Jpn time)-

Title:Fate of spin polarization in a relativistic fluid

Abstract:

Recently, there have been significant experimental progresses in observing and/or controlling spin-dependent bulk quantities in broad areas in physics, e.g., quark-gluon plasma created in heavy-ion collisions and spintronics in condensed-matter physics. Although hydrodynamics is one of the most powerful theoretical frameworks to describe spacetime evolution of bulk quantities, its extension to a spinful fluid has not been developed well, especially for relativistic systems. In this talk, I will explain our work on a phenomenological derivation of relativistic hydrodynamics with a dynamical spin degree of freedom [1]. After explaining a general framework of the entropy-current analysis [2], I will show how spin angular momentum is included in the relativistic hydrodynamic equation. Moreover, with the help of the linear-mode analysis, I will also demonstrate that spin must be a non-hydrodynamic (relaxational) mode due to its nonconservative nature.

References:

[1] K. Hattori, M. Hongo, X-G. Huang, M. Matsuo, H. Taya, Phys.Lett.B 795 (2019) 100-106.

[2] L.D. Landau, E.M. Lifshitz. "Fluid Mechanics (Second Ed.)" Butterworth Heinemann (1987).