scholarly journals Application of the nuclear equation of state obtained by the variational method to core-collapse supernovae

2014 ◽  
Vol 2014 (2) ◽  
pp. 23D05-0 ◽  
Author(s):  
H. Togashi ◽  
M. Takano ◽  
K. Sumiyoshi ◽  
K. Nakazato
Keyword(s):  
Equation Of State ◽  
Variational Method ◽  
Core Collapse ◽  
Nuclear Equation Of State

scholarly journals New Nuclear Equation of State for Core-Collapse Supernovae with the Variational Method

2014 ◽  
Vol 66 ◽  
pp. 07026
Author(s):  
H. Togashi ◽  
S. Yamamuro ◽  
K. Nakazato ◽  
M. Takano ◽  
H. Suzuki ◽  
...  
Keyword(s):  
Equation Of State ◽  
Variational Method ◽  
Core Collapse ◽  
Nuclear Equation Of State

VARIATIONAL CALCULATION FOR THE NUCLEAR EQUATION OF STATE TOWARD SUPERNOVA EXPLOSIONS

2008 ◽  
Vol 23 (27n30) ◽  
pp. 2455-2458
Author(s):  
MASATOSHI TAKANO ◽  
HIROAKI KANZAWA ◽  
KAZUHIRO OYAMATSU ◽  
KOHSUKE SUMIYOSHI
Keyword(s):  
Equation Of State ◽  
Variational Method ◽  
Symmetry Energy ◽  
Nuclear Force ◽  
Variational Calculation ◽  
Expectation Value ◽  
Nuclear Equation Of State ◽  
Supernova Explosions ◽  
Three Body ◽  
Stability Line

The equation of state (EOS) is calculated for uniform nuclear matter at zero and finite temperatures with the variational method. Making use of uncertainty of the three-body nuclear force, adjustable parameters in the nuclear EOS are tuned so that the Thomas-Fermi calculations for β-stable nuclei with the EOS reproduce the empirical data. The calculated nuclear properties imply that larger symmetry energy of the EOS is preferable to reproduce the empirical β-stability line. The expectation value of the nuclear Hamiltonian caused by the 2π-exchange three-body nuclear force is uncertain and related to the symmetry energy.

scholarly journals Equation of state for nuclear matter in core-collapse supernovae by the variational method

2014 ◽  
Vol 569 ◽  
pp. 012058
Author(s):  
H Togashi ◽  
Y Takehara ◽  
S Yamamuro ◽  
K Nakazato ◽  
H Suzuki ◽  
...  
Keyword(s):  
Equation Of State ◽  
Variational Method ◽  
Nuclear Matter ◽  
Core Collapse

scholarly journals Nuclear equation of state for core-collapse supernova simulations with realistic nuclear forces

2017 ◽  
Vol 961 ◽  
pp. 78-105 ◽  
Author(s):  
H. Togashi ◽  
K. Nakazato ◽  
Y. Takehara ◽  
S. Yamamuro ◽  
H. Suzuki ◽  
...  
Keyword(s):  
Equation Of State ◽  
Core Collapse ◽  
Nuclear Forces ◽  
Core Collapse Supernova ◽  
Nuclear Equation Of State

scholarly journals Equation-of-state Dependence of Gravitational Waves in Core-collapse Supernovae

2021 ◽  
Vol 923 (2) ◽  
pp. 201
Author(s):  
Oliver Eggenberger Andersen ◽  
Shuai Zha ◽  
André da Silva Schneider ◽  
Aurore Betranhandy ◽  
Sean M. Couch ◽  
...  
Keyword(s):  
Equation Of State ◽  
Gravitational Waves ◽  
Effective Mass ◽  
State Dependence ◽  
Peak Frequency ◽  
Core Collapse ◽  
Thermal Dependence ◽  
Nuclear Equation Of State ◽  
Strong Excitation ◽  
Rule Out

Abstract Gravitational waves (GWs) provide unobscured insight into the birthplace of neutron stars and black holes in core-collapse supernovae (CCSNe). The nuclear equation of state (EOS) describing these dense environments is yet uncertain, and variations in its prescription affect the proto−neutron star (PNS) and the post-bounce dynamics in CCSN simulations, subsequently impacting the GW emission. We perform axisymmetric simulations of CCSNe with Skyrme-type EOSs to study how the GW signal and PNS convection zone are impacted by two experimentally accessible EOS parameters, (1) the effective mass of nucleons, m ⋆, which is crucial in setting the thermal dependence of the EOS, and (2) the isoscalar incompressibility modulus, K sat. While K sat shows little impact, the peak frequency of the GWs has a strong effective mass dependence due to faster contraction of the PNS for higher values of m ⋆ owing to a decreased thermal pressure. These more compact PNSs also exhibit more neutrino heating, which drives earlier explosions and correlates with the GW amplitude via accretion plumes striking the PNS, exciting the oscillations. We investigate the spatial origin of the GWs and show the agreement between a frequency-radial distribution of the GW emission and a perturbation analysis. We do not rule out overshoot from below via PNS convection as another moderately strong excitation mechanism in our simulations. We also study the combined effect of effective mass and rotation. In all our simulations we find evidence for a power gap near ∼1250 Hz; we investigate its origin and report its EOS dependence.

Nuclear equation of state with the variational method and its application to supernova simulations

2014 ◽  
Vol 29 ◽  
pp. 1460221 ◽  
Author(s):  
Hajime Togashi ◽  
Masatoshi Takano ◽  
Kohsuke Sumiyoshi ◽  
Ken'ichiro Nakazato
Keyword(s):  
Equation Of State ◽  
Variational Method ◽  
Free Energies ◽  
Nuclear Equation Of State ◽  
Variational Calculations ◽  
General Relativistic ◽  
Hypernetted Chain ◽  
Cluster Variational Method ◽  
Three Body ◽  
Body Potential

We report on an equation of state (EOS) of hot asymmetric nuclear matter constructed using the variational method and its application to hydrodynamic simulations of core-collapse supernovae. This nuclear EOS is based on the AV18 two-body potential and UIX three-body potential, and the energy per nucleon at zero temperature is constructed with the cluster variational method. At finite temperatures, the free energies per nucleon are calculated with an extension of the variational method devised by Schmidt and Pandharipande. This EOS is in good agreement with that by the Fermi hypernetted chain variational calculations at zero and finite temperatures, and the structure of neutron stars calculated with this EOS is consistent with recent observational data. Using this nuclear EOS, we perform a spherically symmetric general-relativistic adiabatic simulation of the SN explosion. The explosion energy calculated with our EOS in the present simulation is larger than that obtained with the Shen EOS, implying that the variational EOS is softer than the Shen EOS.

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