2019/01/31 by Koichi Hattori, Masaru Hongo, Xu-Guang Huang +2 · 1 citation
Physics and Astronomy · #Angular momentum #Antisymmetric relation #Boltzmann equation #Boltzmann's entropy formula #Classical mechanics #Entropy (arrow of time) #High-Energy Particle Collisions Research #Mathematical physics #Physics #Pulsars and Gravitational Waves Research #Quantum electrodynamics #Quantum mechanics #Quantum, superfluid, helium dynamics #cond-mat.mes-hall #cond-mat.stat-mech #hep-ph #hep-th #nucl-th
paper · pdf · doi:10.1016/j.physletb.2019.05.040
published as Phys.Lett. B795 (2019) 100-106 · 7 pages
openalex publication_date 2019/06/04 · arxiv created 2019/07/02 · arxiv updated 2019/07/03 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
We derive relativistic hydrodynamic equations with a dynamical spin degree of freedom on the basis of an entropy-current analysis. The first and second laws of local thermodynamics constrain possible structures of the constitutive relations including a spin current and the antisymmetric part of the (canonical) energy-momentum tensor. Solving the obtained hydrodynamic equations within the linear-mode analysis, we find spin-diffusion modes, indicating that spin density is damped out after a characteristic time scale controlled by transport coefficients introduced in the antisymmetric part of the energy-momentum tensor in the entropy-current analysis. This is a consequence of mutual convertibility between spin and orbital angular momentum.