2012/06/30 by Kyosuke Tsumura, Teiji Kunihiro
Engineering · Mathematics · Physics and Astronomy · #Ansatz #Boltzmann equation #Classical mechanics #Fluid Dynamics and Turbulent Flows #Gas Dynamics and Kinetic Theory #High-Energy Particle Collisions Research #Invariant (physics) #Mathematical physics #Physics #Quantum mechanics #Renormalization group #Statistical physics #hep-ph #nucl-th
paper · pdf · doi:10.1140/epja/i2012-12162-x
12 pages. Subsection 4.1 is largely rewritten to elaborate the argument leading to the unique choice of the macroscopic-frame vector as the flow velocity. Some other parts are also modified with some references added to make the discussions precise and clearer. Typos are corrected. Any conclusions are not altered. arXiv admin note: text overlap with arXiv:1205.5843
arxiv created 2012/08/07 · openalex publication_date 2012/11/01 · arxiv updated 2015/06/05 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
We review our work on the application of the renormalization-group method to obtain first- and second-order relativistic hydrodynamics from the relativistic Boltzmann equation (RBE) as a dynamical system, with some corrections and new unpublished results. For the first-order equation, we explicitly obtain the distribution function in the asymptotic regime as the invariant manifold of the dynamical system, which turns out to be nothing but the matching condition defining the energy frame, i.e., the Landau-Lifshitz one. It is argued that the frame on which the flow of the relativistic hydrodynamic equation is defined must be the energy frame, if the dynamics should be consistent with the underlying RBE. A sketch is also given for derivation of the second-order hydrodynamic equation, i.e., extended thermodynamics, which is accomplished by extending the invariant manifold so that it is spanned by excited modes as well as the zero modes (hydrodynamic modes) of the linearized collision operator. On the basis of thus constructed resummed distribution function, we propose a novel ansatz for the functional form to be used in Grad moment method; it is shown that our theory gives the same expressions for the transport coefficients as those given in the Chapman-Enskog theory as well as the novel expressions for the relaxation times and lengths allowing natural interpretation.