Waseda University · 물리·천문학
이 교수의 연구실은 핵심적으로 중성자별 붕괴 및 이중성자별 융합과 같은 극한 천체 환경에서 발생하는 중성자율의 집단적 행동, 특히 중성자율 변환 현상인 '충돌성 중성자율 불안정성'(CFI)과 '빠른 중성자율 변환'(FFC)을 중심으로 연구를 전개하고 있습니다. 선형 안정성 분석과 비선형 수치 시뮬레이션을 바탕으로 중성자율의 비대칭성, 비균질성, 그리고 입자 상호작용의 역할을 깊이 있게 분석하며, 특히 공명 현상이 CFI의 성장률을 수개의 지수만큼 증폭시킬 수 있음을 규명했습니다. 이는 초신성 폭발 메커니즘과 중성자별 병합에서 중성자율의 최종 분포를 이해하는 데 핵심적입니다.
표시된 성과는 수집된 데이터 기준으로 산출되며, 일부 차이가 있을 수 있습니다.
Investigations on the resonancelike phenomenon in the collisional flavor instability (CFI) of neutrinos, which were observed in the linear phase recently, are reported. We show that it occurs not only for the isotropy-preserving modes as pointed out in the previous work but also for the isotropy-breaking modes and that it enhances the linear growth rate of the CFI. Employing linear analysis and nonlinear numerical simulations in the two-flavor scheme and under the relaxation approximation for th
Neutrinos are known to undergo flavor conversion processes among the three flavors. The fast flavor conversion (FFC) has been the central piece of flavor conversions taking place in core-collapse supernovae (CCSNe) due to its shorter timescale to the completion of flavor conversion compared to other types of flavor conversion. Although the ordinary collisions between neutrinos and matter were once thought to decohere neutrinos and thus damp flavor conversions, it was recently realized that they
In astrophysical environments such as core-collapse supernovae (CCSNe) and binary neutron star mergers (BNSMs), neutrinos potentially experience substantial flavor mixing due to the refractive effects of neutrino self-interactions. Determining the survival probability of neutrinos in asymptotic states is paramount to incorporating flavor conversions' effects in the theoretical modeling of CCSN and BNSM. Some phenomenological schemes have shown good performance in approximating asymptotic states
Neutrinos are known to undergo flavor conversion among their three flavors. In the theoretical modeling of core-collapse supernova, there has been a great deal of attention to recent discoveries of a new type of neutrino flavor conversions, namely collisional flavor instability (CFI), in which the instability is induced by the flavor-dependent decoherence due to the disparity of neutrino-matter interactions among flavors. In this paper, we study how the appearance of on-shell muons and associate
Investigations on the resonance in the collisional flavor instability (CFI) of neutrinos, which were reported recently, are reported. We show that the resonance occurs not only for the isotropy-preserving modes as pointed out in the previous work but also for the isotropy-breaking modes and that it enhances the growth rate of CFI by orders of magnitude. Employing the linear analysis and nonlinear numerical simulations in the two-flavor scheme and under the relaxation approximation for the collis
Dense neutrino systems, which display collectivity mediated by the weak interaction, have deep parallels with mean-field kinetic systems governed by other fundamental forces. We identify analogues in fast flavor conversion (FFC) of some time-honored nonlinear phenomena in plasmas and self-gravitating systems. We focus in particular on nonlinear Landau damping and collisionless equilibria, which are likely important pieces of the unsolved puzzle of neutrino oscillations in core-collapse supernova
Neutrinos are known to undergo flavor conversion processes among the three flavors. The fast flavor conversion (FFC) has been the central piece of flavor conversions taking place in core-collapse supernovae (CCSNe) due to its shorter timescale to the completion of flavor conversion compared to other types of flavor conversion. Although the ordinary collisions between neutrinos and matter were once thought to decohere neutrinos and thus damp flavor conversions, it was recently realized that they
Impedance analysis is usually used to study the stability of high proportion new energy systems, which needs to know the impedance of the grid-connected converter. However, traditional impedance modeling methods usually simplify the modulation part to unit gain, which affects the modeling accuracy. To address this issue, an experimental and mechanistic hybrid impedance modeling approach for grid-connected converters considering modulation deviation is proposed. Since the deviation value between
In astrophysical environments such as core-collapse supernovae (CCSNe) and binary neutron star mergers (BNSMs), neutrinos potentially experience substantial flavor mixing due to the refractive effects of neutrino self-interactions. Determining the survival probability of neutrinos in asymptotic states is paramount to incorporating flavor conversions' effects in the theoretical modeling of CCSN and BNSM. Some phenomenological schemes have shown good performance in approximating asymptotic states
