Classical Neutrino Kinetics in Core Collapse Supernovae, The Ultimate Goal: Rationale, Requirements, Constraints, Implementations, and Outlook
Presenter
July 11, 2024
Abstract
It is now well established that neutrinos can drive core collapse supernova explosions and likely do for the lion’s share of observed events in the Universe. They are center stage in the modeling of core collapse supernovae and dominate the computational cost in all realistic models, given the need for a kinetics treatment of neutrino production, transport, and interaction in the cores of massive stars. Neutrino mean free paths range over orders of magnitude, and a fluid description is not accurate except in the innermost regions of these cores. The ultimate classical description of such kinetics would be achieved by solving the Boltzmann kinetic equations for all flavors of neutrinos and antineutrinos produced. Boltzmann kinetics would then provide a sound foundation for the extension to quantum kinetics in order to incorporate neutrino flavor transformations that are expected to occur, which may impact one or all of the following: the explosion mechanism, nucleosynthesis, and terrestrial neutrino signatures. The modeling of neutrino kinetics in core collapse supernovae is compounded by the fact that lepton number and energy must be conserved simultaneously and that the neutrino distribution functions must be bounded given the Fermi-Dirac statistics obeyed by these Fermions. Success in arriving at implementations of Boltzmann neutrino kinetics in future core collapse supernova models will require reformulations of the fundamental equations and the development of discretizations for these equations, that conserve lepton number and energy, are realizable – i.e., maintain boundedness of the neutrino distributions – and are computationally efficient. I will discuss each of these topics, as well as indicate progress to date in achieving our ultimate goal, by our group and others.