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arXiv · 2309.03526

General-relativistic radiation transport scheme in Gmunu II: Implementation of novel microphysical library for neutrino radiation -- Weakhub

Harry Ho-Yin Ng·Patrick Chi-Kit Cheong·Alan Tsz-Lok Lam·Tjonnie Guang Feng Li
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Abstract

We introduce \texttt{Weakhub}, a novel neutrino microphysics library that provides opacities and kernels beyond conventional interactions used in the literature. This library includes neutrino-matter, neutrino-photon, and neutrino-neutrino interactions, along with corresponding weak and strong corrections. A full kinematics approach is adopted for the calculations of $\beta$-processes, incorporating various weak corrections and medium modifications due to the nuclear equation of state. Calculations of plasma processes, electron neutrino-antineutrino annihilation, and nuclear de-excitation are included. We also present the detailed derivations of weak interactions and the coupling of them to the two-moment based general-relativistic multi-group radiation transport in the \texttt{G}eneral-relativistic \texttt{mu}ltigrid \texttt{nu}merical (\texttt{Gmunu}) code. We compare the neutrino opacity spectra for all interactions and estimate their contributions at hydrodynamical points in core-collapse supernova and binary neutron star postmerger remnant, and predict the effects of improved opacities in comparison to conventional ones for a binary neutron star postmerger at a specific hydrodynamical point. We test the implementation of the conventional set of interactions by comparing it to an open-source neutrino library \texttt{NuLib} in a core-collapse supernova simulation. We demonstrate good agreement with discrepancies of less than $\sim 10\%$ in luminosity for all neutrino species, while also highlighting the reasons contributing to the differences. To compare the advanced interactions to the conventional set in core-collapse supernova modelling, we perform simulations to analyze their impacts on neutrino signatures, hydrodynamical behaviors, and shock dynamics, showing significant deviations.

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Harry Ho-Yin Ng, Patrick Chi-Kit Cheong, Alan Tsz-Lok Lam, Tjonnie Guang Feng Li. 2023-09-07. General-relativistic radiation transport scheme in Gmunu II: Implementation of novel microphysical library for neutrino radiation -- Weakhub. https://doi.org/10.3847/1538-4365%2Fad2fbd

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