scholarly journals Dimension dependence of numerical simulations on gravitational waves from protoneutron stars

2020 ◽  
Vol 102 (2) ◽  
Author(s):  
Hajime Sotani ◽  
Tomoya Takiwaki
Keyword(s):  
Numerical Simulations ◽  
Gravitational Waves ◽  
Protoneutron Stars

scholarly journals Numerical simulations of gravitational waves from early-universe turbulence

2020 ◽  
Vol 102 (8) ◽  
Author(s):  
Alberto Roper Pol ◽  
Sayan Mandal ◽  
Axel Brandenburg ◽  
Tina Kahniashvili ◽  
Arthur Kosowsky
Keyword(s):  
Numerical Simulations ◽  
Gravitational Waves ◽  
Early Universe

scholarly journals Gravitational waves from binary black hole mergers surrounded by scalar field clouds: Numerical simulations and observational implications

2021 ◽  
Vol 103 (4) ◽  
Author(s):  
Sunil Choudhary ◽  
Nicolas Sanchis-Gual ◽  
Anshu Gupta ◽  
Juan Carlos Degollado ◽  
Sukanta Bose ◽  
...  
Keyword(s):  
Black Hole ◽  
Scalar Field ◽  
Numerical Simulations ◽  
Gravitational Waves ◽  
Binary Black Hole

scholarly journals Binary Neutron Star and Short Gamma-Ray Burst Simulations in Light of GW170817

Galaxies ◽  
2018 ◽  
Vol 6 (4) ◽  
pp. 119 ◽  
Author(s):  
Antonios Nathanail
Keyword(s):  
Neutron Star ◽  
Gravitational Wave ◽  
Electromagnetic Radiation ◽  
Numerical Simulations ◽  
Gravitational Waves ◽  
Gamma Ray ◽  
Numerical Relativity ◽  
Gamma Ray Burst ◽  
Binary Neutron Star ◽  
The Status

In the dawn of the multi-messenger era of gravitational wave astronomy, which was marked by the first ever coincident detection of gravitational waves and electromagnetic radiation, it is important to take a step back and consider our current established knowledge. Numerical simulations of binary neutron star mergers and simulations of short GRB jets must combine efforts to understand such complicated and phenomenologically rich explosions. We review the status of numerical relativity simulations with respect to any jet or magnetized outflow produced after merger. We compare what is known from such simulations with what is used and obtained from short GRB jet simulations propagating through the BNS ejecta. We then review the established facts on this topic, as well as discuss things that need to be revised and further clarified.

scholarly journals Avoided crossing in gravitational wave spectra from protoneutron star

2020 ◽  
Vol 498 (3) ◽  
pp. 3503-3512
Author(s):  
Hajime Sotani ◽  
Tomoya Takiwaki
Keyword(s):  
Numerical Simulations ◽  
Gravitational Waves ◽  
Supernova Explosion ◽  
Average Density ◽  
Linear Perturbation ◽  
Avoided Crossing ◽  
Supernova Explosions ◽  
Later Phase ◽  
Protoneutron Star ◽  
Selection Of

ABSTRACT The ramp up signals of gravitational waves appearing in the numerical simulations could be important signals to estimate parameters of the protoneutron star (PNS) at supernova explosions. To identify the signals with PNS oscillations, we make a linear perturbation analysis and compare the resultant eigenfrequencies with the ramp up signals obtained via the 2D numerical simulations. Then, we find that the ramp up signals correspond well to the g1-mode in the early phase and to the f-mode, to which the g1-mode is exchanged via the avoided crossing. We also confirm that the f- and g1-modes are almost independent of the selection of the PNS surface density in the later phase after core bounce. In addition, we successfully find that the fitting formula of g1- and f-modes, which correspond to the ramp up signals in the numerical simulation, as a function of the PNS average density. That is, via the direct observation of the gravitational waves after supernova explosion, one could extract the time evolution of the PNS average density using our fitting formula.

scholarly journals Numerical Relativity as a Tool for Studying the Early Universe

2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
David Garrison
Keyword(s):  
Dark Matter ◽  
Magnetic Fields ◽  
Numerical Simulations ◽  
Gravitational Waves ◽  
Early Universe ◽  
Large Scale ◽  
Numerical Relativity ◽  
Turbulent Plasma ◽  
The University ◽  
Scalar Perturbations

Numerical simulations are becoming a more effective tool for conducting detailed investigations into the evolution of our universe. In this paper, we show how the framework of numerical relativity can be used for studying cosmological models. The author is working to develop a large-scale simulation of the dynamical processes in the early universe. These take into account interactions of dark matter, scalar perturbations, gravitational waves, magnetic fields, and turbulent plasma. The code described in this report is a GRMHD code based on the Cactus framework and is structured to utilize one of several different differencing methods chosen at run-time. It is being developed and tested on the University of Houston’s Maxwell cluster.

Gravitational waves from dynamical shape transition of protoneutron stars

2021 ◽  
pp. 2150104
Author(s):  
H. Rodrigues ◽  
J. A. Rosero-Gil ◽  
A. M. Endler ◽  
S. B. Duarte ◽  
M. Chiapparini
Keyword(s):  
Angular Momentum ◽  
Gravitational Waves ◽  
Equilibrium Configuration ◽  
Equations Of Motion ◽  
Dynamical Behavior ◽  
Dynamical Evolution ◽  
Angular Frequency ◽  
Triaxial Ellipsoid ◽  
Shape Transition ◽  
Protoneutron Stars

We describe the dynamical behavior of newborn neutron stars modelled as homogeneous rotating spheroids. The dynamical evolution is triggered by the escape of trapped neutrinos, providing the initial equilibrium configuration. It is shown that for a given set of values of the initial angular momentum, a shape transition to a triaxial ellipsoid configuration occurs. Gravitational waves are then generated by the breaking of the axial symmetry, and some aspects of their observation are discussed. We found a narrow window for both, the initial values of the angular frequency and the eccentricity, able to enable a dynamical shape transition, with their upper bound determined by the Kepler frequency. The energy and angular momentum carried away by the gravitational wave are treated consistently with the solution of the equations of motion of the system.

Sign in / Sign up

Export Citation Format

Share Document