Comparative Testing of Subgrid Models for Fast Neutrino Flavor Conversions in Core-collapse Supernova Simulations

Fuente: arXiv
Gespeichert in:
Bibliographische Detailangaben
Hauptverfasser: Akaho, Ryuichiro, Nagakura, Hiroki, Yamada, Shoichi
Format: Preprint
Veröffentlicht: 2025
Schlagworte:
Online-Zugang:
Tags: Tag hinzufügen
Keine Tags, Fügen Sie den ersten Tag hinzu!
_version_ 1866916911667740672
author Akaho, Ryuichiro
Nagakura, Hiroki
Yamada, Shoichi
author_facet Akaho, Ryuichiro
Nagakura, Hiroki
Yamada, Shoichi
contents We investigate key methodologies of Bhatnagar-Gross-Krook subgrid modeling for neutrino fast flavor conversions (FFC) in core-collapse supernova based on spherically symmetric Boltzmann radiation hydrodynamics simulations. We first examine time integration methods (explicit, implicit, or semi-implicit) and time step control for the subgrid term, and then compare various approaches in the literature approximating FFCs in two aspects: (1) angular dependent survival probability of neutrinos versus simple equipartition condition with a certain baryon mass density threshold, and (2) 4-species treatment versus 3-species assumption ($ν_x=\barν_x$). We find that the equipartition condition is reasonable for out-going neutrinos, but large deviations emerge in the incoming neutrinos, that has an influence on matter profiles. We also find that the 3-species model, in which flavor conversions evolve towards erasing electron neutrino lepton number (ELN) crossings, behave differently from the 4-species models where heavy leptonic neutrino number (XLN) are appropriately treated in FFC subgrid modeling. In 4-species models, we commonly observe noticeable differences between $ν_x$ and $\barν_x$, highlighting the limitation in 3-species treatments to study impacts of flavor conversion on neutrino signals. Our result also suggests that FFC models yield lower neutrino heating rate and smaller shock radii compared to cases with no FFC, in agreement with earlier studies employing quantum kinetic neutrino transport. This work provides valuable information towards robust implementation of FFC subgrid model into classical transport, and serves as a pilot study for future multi-dimensional simulations.
format Preprint
id arxiv_https___arxiv_org_abs_2506_07017
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Comparative Testing of Subgrid Models for Fast Neutrino Flavor Conversions in Core-collapse Supernova Simulations
Akaho, Ryuichiro
Nagakura, Hiroki
Yamada, Shoichi
High Energy Astrophysical Phenomena
We investigate key methodologies of Bhatnagar-Gross-Krook subgrid modeling for neutrino fast flavor conversions (FFC) in core-collapse supernova based on spherically symmetric Boltzmann radiation hydrodynamics simulations. We first examine time integration methods (explicit, implicit, or semi-implicit) and time step control for the subgrid term, and then compare various approaches in the literature approximating FFCs in two aspects: (1) angular dependent survival probability of neutrinos versus simple equipartition condition with a certain baryon mass density threshold, and (2) 4-species treatment versus 3-species assumption ($ν_x=\barν_x$). We find that the equipartition condition is reasonable for out-going neutrinos, but large deviations emerge in the incoming neutrinos, that has an influence on matter profiles. We also find that the 3-species model, in which flavor conversions evolve towards erasing electron neutrino lepton number (ELN) crossings, behave differently from the 4-species models where heavy leptonic neutrino number (XLN) are appropriately treated in FFC subgrid modeling. In 4-species models, we commonly observe noticeable differences between $ν_x$ and $\barν_x$, highlighting the limitation in 3-species treatments to study impacts of flavor conversion on neutrino signals. Our result also suggests that FFC models yield lower neutrino heating rate and smaller shock radii compared to cases with no FFC, in agreement with earlier studies employing quantum kinetic neutrino transport. This work provides valuable information towards robust implementation of FFC subgrid model into classical transport, and serves as a pilot study for future multi-dimensional simulations.
title Comparative Testing of Subgrid Models for Fast Neutrino Flavor Conversions in Core-collapse Supernova Simulations
topic High Energy Astrophysical Phenomena
url https://arxiv.org/abs/2506.07017