Quantum closures for neutrino moment transport

Year: 2025

Type: article

Abstract: A computationally efficient method for calculating the transport of neutrino flavor in simulations is to use angular moments of the neutrino one-body reduced density matrix, i.e., “quantum moments.” As with any moment-based radiation transport method, a closure is needed if the infinite tower of moment evolution equations is truncated. We derive a general parametrization of a quantum closure and the limits the parameters must satisfy in order for the closure to be physical. We then derive from multiangle calculations the evolution of the closure parameters in two test cases which we then progressively insert into a moment evolution code and show how the parameters affect the moment results until the full multiangle results are reproduced. This parametrization paves the way to setting prescriptions for genuine quantum closures adapted to neutrino transport in a range of situations.

Source: Physical review. D/Physical review. D.

DOI: 10.1103/physrevd.111.063046

Authors: James P. Kneller, Julien Froustey, Evan B. Grohs, Francois Foucart, Gail C. McLaughlin, Sherwood Richers

Institutions: University of California, Berkeley, University of New Hampshire, North Carolina State University, University of Tennessee at Knoxville

Language: English

Topic: Neutrino Physics Research

Subfield: Nuclear and High Energy Physics

Field: Physics and Astronomy

Domain: Physical Sciences

Open Access status: hybrid

Funders: National Science Foundation, U.S. Department of Energy, National Aeronautics and Space Administration, Emergency Nurses Association Foundation, North Carolina State University, Nuclear Safety and Security Commission, Office of Science, Nuclear Physics

OpenAlex ID: W4408505234