Physical, numerical, and computational challenges of modeling neutrino transport in core-collapse supernovae

Abstract

The proposal that core collapse supernovae are neutrino driven is still the subject of active investigation more than fifty years after the seminal paper by Colgate and White. The modern version of this paradigm, which we owe to Wilson, proposes that the supernova shock wave is powered by neutrino heating, mediated by the absorption of electron-flavor neutrinos and antineutrinos emanating from the protoneutron star surface, or neutrinosphere. Neutrino weak interactions with the stellar core fluid, the theory of which is still evolving, are flavor and energy dependent. The associated neutrino mean free paths extend over many orders of magnitude and are never always small relative to the stellar core radius. Thus, neutrinos are never always fluid like. Instead, a kinetic description of them in terms of distribution functions that determine the number density of neutrinos in the six-dimensional phase space of position, direction, and energy, for both neutrinos and antineutrinos of each flavor, or in terms of angular moments of these neutrino distributions that instead provide neutrino

Detecting and reconstructing gravitational waves from the next Galactic core-collapse supernova in the Advanced Detector Era

“…While the explosion mechanism is currently not settled (see [7] for a review), it is believed that the massive flux of neutrinos from the PNS plays a crucial role. In this so-called neutrino-driven mechanism, the neutrinos heat up the matter creating a shock that eventually may blow up the star (see [24,53] for a review). When a progenitor star rotates rapidly and has a strong magnetic field, the magnetorotationally-driven (MHD-driven) mechanism is more likely to explain a CCSN explosion.…”

“…In this scenario, rapid rotation flattens the iron core, producing an axisymmetric collapse and a strong linearly polarized GW bounce signal. The latter stages after bounce are not yet well understood because of insufficient MHD microphysics in the numerical simulations (even if very active research is ongoing [24,25]). Regardless of the progenitor star rotation, if the shock is not revived and the matter continues to fall, the PNS can collapse further to a BH.…”

“…Although the predicted signal morphologies are uncertain, some consensus emerged from the multidimensional supernova simulations [24][25][26]. This knowledge is useful for improving the existing methods for searches, reconstructing waveforms, and inferring physical properties.…”

A New Moment-Based General-Relativistic Neutrino-Radiation Transport Code: Methods and First Applications to Neutron Star Mergers

“…Neutrinos mediate the transport of energy and lepton number in dense and hot environments. As such, neutrinos play a crucial role in powering the explosion of massive stars as core-collapse supernovae (Melson et al 2015;Lentz et al 2015;O'Connor & Couch 2018b;Burrows et al 2020;Burrows & Vartanyan 2021;Bollig et al 2021;Mezzacappa et al 2020), in the cooling of the protoneutron star (Roberts & Reddy 2016) and in the synthesis of heavy elements neutrino-driven winds (Arcones & Thielemann 2013). Neutrinos also determine the composition and the final r-process nucleosynthesis yields of the dynamical ejecta from neutron star (NS) mergers (Sekiguchi et al 2015;Foucart et al 2016a;Radice et al 2016;Sekiguchi et al 2016;Perego et al 2017b).…”

Supernova Constraint on Self-Interacting Dark Sector Particles

“…We use a widely-examined dark photon portal dark sector model explicitly to compute all the relevant interaction cross-sections and the decay rates. In principle, to determine precisely the dark sector particle fluxes emerging from the PNS requires solving full Boltzmann transport equations in a way similar to the neutrino transport problem in SNe (see e.g., a recent review [72] and references TABLE I: Relevant processes of dark photon interactions considered in this work. "Abs."…”