A5065617542- Pulsars and Gravitational Waves Research
- Astrophysical Phenomena and Observations
- Black Holes and Theoretical Physics
- Cosmology and Gravitation Theories
- Relativity and Gravitational Theory
- Geophysics and Gravity Measurements
- Adaptive optics and wavefront sensing
- Gamma-ray bursts and supernovae
- Particle physics theoretical and experimental studies
- Meteorological Phenomena and Simulations
- Computational Physics and Python Applications
- Solar and Space Plasma Dynamics
- Computational Fluid Dynamics and Aerodynamics
- Stellar, planetary, and galactic studies
- Particle Accelerators and Free-Electron Lasers
- Geophysics and Sensor Technology
- Fluid Dynamics and Turbulent Flows
- Experimental and Theoretical Physics Studies
Washburn University
2002-2022
Max Planck Institute for Gravitational Physics
1997-2002
University of Kansas
2002
Max Planck Society
1997-1999
Pennsylvania State University
1998-1999
University of Illinois Urbana-Champaign
1998
National Center for Supercomputing Applications
1998
Binary black-hole interactions provide potentially the strongest source of gravitational radiation for detectors currently under development. We present some results from Black Hole Grand Challenge Alliance three-dimensional Cauchy evolution module. These constitute essential steps towards modeling such and predicting waveforms. report on single evolutions first successful demonstration a black hole moving freely through computational grid via evolution: near 6M at 0.1c during total duration...
We present a method for extracting gravitational radiation from three-dimensional numerical relativity simulation and, using the extracted data, to provide outer boundary conditions. The treats dynamical variables as nonspherical perturbations of Schwarzschild geometry. discuss code which implements this and results tests have been performed with code.Received 29 September 1997DOI:https://doi.org/10.1103/PhysRevLett.80.1812©1998 American Physical Society
We report new results which establish that the accurate three-dimensional numerical simulation of generic single-black-hole spacetimes has been achieved by characteristic evolution with unlimited long term stability. Our include distorted, moving, and spinning single black holes, times up to 60000M.Received 12 January 1998DOI:https://doi.org/10.1103/PhysRevLett.80.3915©1998 American Physical Society
We have developed a general method for finding apparent horizons in 3D numerical relativity. Instead of solving the partial differential equation describing location horizons, we expand closed 2D surfaces terms symmetric trace--free tensors and solve expansion coefficients using minimization procedure. Our is applied to number different spacetimes, including numerically constructed spacetimes containing highly distorted axisymmetric black holes spherical coordinates, rotating, colliding...
Abstract We present results from general relativistic calculations of the tidal disruption white dwarf stars near encounters with intermediate-mass black holes. follow evolution 0.2 M ⊙ and 0.6 on parabolic trajectories that approach 10 3 –10 4 holes as close a few Schwarzschild radii at periapsis, paying particular attention to effect has thermonuclear reactions synthesis heavy elements. These create diverse environments are characteristic Type I supernovae capable producing both elements...
We present three-dimensional, {\it non-axisymmetric} distorted black hole initial data which generalizes the axisymmetric, distorted, non-rotating [Bernstein93a] and rotating [Brandt94a] single developed by Bernstein, Brandt, Seidel. These should be useful for studying dynamics of fully 3D, holes, such as those created spiraling coalescence two holes. describe mathematical construction several families sets, show how to construct numerical solutions. survey quantities associated with...
We consider the numerical evolution of black hole initial data sets, consisting single holes distorted by strong gravitational waves, with a full 3D, nonlinear code. These sets mimic late stages coalescing holes. compare various aspects axisymmetric obtained this 3D code, to results from well established In both codes we examine and behavior metric functions, apparent horizon properties, waveforms, show that these dynamic can be accurately evolved in 3D. particular present computational...
This paper presents a numerical study over wide parameter space of the likelihood dynamical bar-mode instability in differentially rotating magnetized neutron stars. The innovative aspect this is incorporation magnetic fields such context, which have thus far been neglected purely hydrodynamical simulations available literature. investigation uses Cosmos++ code allows us to perform three dimensional on cylindrical grid at high resolution. A sample Newtonian magneto-hydrodynamical starting...
We consider the numerical evolution of dynamic black hole initial data sets with a full 3D, nonlinear code. These consist single holes distorted by strong gravitational waves, and mimic late stages coalescing holes. Through comparison results from well established axisymmetric codes, we show that these can be accurately evolved. In particular, present computational resources techniques, process excitation ringdown evolved, one now extract waves emitted 3D Cartesian metric functions, even...
We present the first results for Cauchy nonlinear evolution of 3D, nonaxisymmetric distorted black holes. focus on extraction and verification 3D waveforms determined by numerical relativity. show that hole can be accurately followed through ringdown period, comparing with a recently developed perturbative technique, we many in spectrum modes, such as l=2 l=4, including weakly excited modes m not zero, evolved extracted from full evolution. also identify new physics contained higher due to...
We consider a series of distorted black hole initial data sets, and develop techniques to evolve them using the linearized equations motion for gravitational wave perturbations on Schwarzschild background. apply this 2D 3D spacetimes. In 2D, waveforms different modes radiation are presented, comparing full nonlinear evolutions axisymmetric l-modes with perturbative evolutions. show how codes solving full, Einstein capable very accurate evolutions, also these aid in studying effects. we...
A code and methodology are introduced for solving the fully general relativistic magnetohydrodynamic (GRMHD) equations using time-explicit, finite-volume discretization. The has options GRMHD traditional artificial-viscosity (AV) or non-oscillatory central difference (NOCD) methods, a new extended AV (eAV) scheme together with dual energy-flux-conserving formulation. energy approach allows accurate modeling of highly flows at boost factors well beyond what been achieved to date by standard...
Abstract We study the initiation of thermonuclear detonations in tidally disrupted white dwarf stars by intermediate-mass (10 3 M ⊙ ) black holes. The length scales required to resolve mechanism are not easily reached 3D, so instead we have devised 2D proxy models, which, together with a logarithmic gridding strategy, can adequately capture detonation wave fronts as material undergoes simultaneous compression and stretching from tidal forces. consider 0.15 0.6 parameterized strengths range β...
We present a new class of 3D black hole initial data sets for numerical relativity. These go beyond the axisymmetric, ``gravity wave plus rotating hole'' single by creating dynamic, distorted with adjustable distortion parameters in 3D. extend our existing test beds relativity, representing late stages binary collisions resulting from on-axis collision or spiralling coalescence, and should provide insight into physics such systems. describe construction these sets, properties number example...
We consider the numerical evolution of dynamic black hole initial data sets with a full 3D, nonlinear code. These consist single holes distorted by strong gravitational waves, and mimic late stages coalescing holes. Through comparison results from well established axisymmetric codes, we show that these can be accurately evolved. In particular, present computational resources techniques, process excitation ringdown evolved, one now extract waves emitted 3D Cartesian metric functions, even...
Numerical relativity is finally coming of age with the development massively parallel computers. 3D problems, which were completely intractable several years ago due to limited computer power, can now be performed grid sizes about $200^3$. We report on new codes developed for solving full Einstein equations, and present results using them evolve black holes gravitational waves.