A5039882253- Pulsars and Gravitational Waves Research
- Astrophysical Phenomena and Observations
- Cosmology and Gravitation Theories
- Black Holes and Theoretical Physics
- Geophysics and Gravity Measurements
- Gamma-ray bursts and supernovae
- Relativity and Gravitational Theory
- Astro and Planetary Science
- Stellar, planetary, and galactic studies
- Geophysics and Sensor Technology
- Solar and Space Plasma Dynamics
- Astronomical Observations and Instrumentation
- Quantum Electrodynamics and Casimir Effect
- High-pressure geophysics and materials
- Astrophysics and Cosmic Phenomena
- Magnetic confinement fusion research
- Geomagnetism and Paleomagnetism Studies
- Experimental and Theoretical Physics Studies
- Space Satellite Systems and Control
- Astronomy and Astrophysical Research
- Superconducting Materials and Applications
- Particle Accelerators and Free-Electron Lasers
- Astrophysics and Star Formation Studies
- Mechanics and Biomechanics Studies
- Inertial Sensor and Navigation
University of North Carolina at Chapel Hill
2014-2023
North Carolina State University
2023
Nazarbayev University
2016
Max Planck Institute for Gravitational Physics
2013
Cornell University
1994
Alfred P. Sloan Foundation
1992
California Institute of Technology
1988-1989
University of Illinois Urbana-Champaign
1985-1986
Western Kentucky University
1980
view Abstract Citations (772) References (29) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Simulation of Magnetohydrodynamic Flows: A Constrained Transport Model Evans, Charles R. ; Hawley, John F. We discuss an optimal strategy for treating the magnetohydrodynamic (MHD) field transport (induction) equation. The induction equation is shown to assume its simplest form when written in terms contravariant forms velocity and magnetic vector density. approach...
view Abstract Citations (465) References (19) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS The Tidal Disruption of a Star by Massive Black Hole Evans, Charles R. ; Kochanek, Christopher S. Results are reported from three-dimensional numerical calculation the tidal disruption low-mass main-sequence star on parabolic orbit around massive black hole (Mh = 10 to 6th stellar mass). postdisruption evolution is followed until hydrodynamic forces becomes...
We observe critical phenomena in spherical collapse of radiation fluid. A sequence spacetimes S[\ensuremath{\eta}] is numerically computed, containing models (\ensuremath{\eta}\ensuremath{\ll}1) that adiabatically disperse and (\ensuremath{\eta}\ensuremath{\gg}1) form a black hole. Near the point (${\mathrm{\ensuremath{\eta}}}_{\mathit{c}}$), evolutions develop self-similar region within which balanced by strong, inward-moving rarefaction wave holds m(r)/r constant as function coordinate...
We report a second example of critical behavior in gravitational collapse. Collapse axisymmetric wave packets is computed numerically for one-parameter family initial data. A black hole first appears along the sequence at parameter value ${\mathit{p}}^{\mathrm{*}}$. As with spherical scalar-field collapse, power law found to relate black-hole mass (the order parameter) and separation:...
We model the inspiral of a compact stellar-mass object into massive nonrotating black hole including all dissipative and conservative first-order-in-the-mass-ratio effects on orbital motion. The techniques we develop allow inspirals with initial eccentricities as high $e\sim0.8$ separations large $p\sim 50$ to be evolved through many thousands orbits up onset plunge hole. is computed using an osculating elements scheme driven by hybridized self-force model, which combines Lorenz-gauge...
view Abstract Citations (99) References (30) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Determing gravitational radiation from Newtonian self-gravitating systems. Finn, Lee Samuel ; Evans, Charles R. Quadrupole formulas are tested and compared in a calculation of rotating stellar core collapse. While the standard quadrupole formula (SQF) allows an economical waveform postlinear gravity, it has several shortcomings that become apparent finite difference...
view Abstract Citations (121) References (40) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Degenerate Dwarf Binaries as Promising, Detectable Sources of Gravitational Radiation Evans, Charles R. ; Iben, Icko, Jr. Smarr, Larry The authors discuss the implications for gravitational wave astronomy a recently hypothesized population double degenerate dwarf binaries (DDBs). In theoretical studies stellar evolution intermediate-mass binary systems, remnant...
Particle production due to a quantized, massless, minimally coupled scalar field in two-dimensional flat spacetime with an accelerating mirror is investigated, focus on the time dependence of process. We analyze first classes trajectories previously investigated by Carlitz and Willey Walker Davies. then four new trajectories, all which can be expressed analytically for several ancillary properties derived analytically. The through use wave packets modes quantized that are out vacuum state....
An exact correspondence between a black hole and an accelerating mirror is demonstrated. It shown that for massless minimally coupled scalar field, the same Bogolubov coefficients connecting ``in'' ``out'' states occur ($1+1$)-dimensional flat spacetime with particular perfectly reflecting boundary trajectory curved in which null shell collapses to form hole. Generalization of latter ($3+1$)-dimensional case discussed. The spectral dynamics computed both spacetimes along energy flux mirror....
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 calculate the evolution and gravitational-wave emission of a spinning compact object inspiraling into substantially more massive (nonrotating) black hole. extend our previous model for nonspinning binary [Phys. Rev. D 93, 064024 (2016)] to include Mathisson-Papapetrou-Dixon spin-curvature force. For spin-aligned binaries we dephasing inspiral associated waveforms relative models that do not effects. find this can be either positive or negative depending on initial separation binary. in...
view Abstract Citations (94) References (65) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Physical Processes in Eclipsing Pulsars: Eclipse Mechanisms and Diagnostics Thompson, C. ; Blandford, R. D. Evans, Charles Phinney, E. S. We investigate how the radio emission of a pulsar interacts with plasma derived from stellar companion. Various physical mechanisms that can cause pulse eclipse are discussed, predictions made for polarization properties emergent...
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 calculate the gravitational perturbations produced by a small mass in eccentric orbit about much more massive Schwarzschild black hole and use numerically computed to solve for metric. The calculations are initially made frequency domain provide Fourier-harmonic modes gauge-invariant master functions that satisfy inhomogeneous versions of Regge-Wheeler Zerilli equations. These equations have specific singular sources containing both delta function derivative-of-delta terms. demonstrate...
view Abstract Citations (70) References (20) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS A Test Suite for Magnetohydrodynamical Simulations Stone, James M. ; Hawley, John F. Evans, Charles R. Norman, Michael L. collection is presented of MHD problems that will provide researchers who have interests in modeling phenomena with a battery tests (a 'test suite') calibrating their numerical algorithms. Use these common reference comparison different The test...
We present an algorithm for calculating the metric perturbations and gravitational self-force extreme-mass-ratio inspirals (EMRIs) with eccentric orbits. The massive black hole is taken to be Schwarzschild, are computed in Lorenz gauge. perturbation equations solved as coupled systems of ordinary differential frequency domain. Accurate local behavior attained through use method extended homogeneous solutions, mode-sum regularization used find self-force. focus on sufficient accuracy ensure...
We present new results through 7PN order on the energy flux from eccentric extreme-mass-ratio binaries. The black hole perturbation calculations are made at very high accuracy (200 decimal places) using a Mathematica code based Mano-Suzuki-Takasugi analytic function expansion formalism. All published coefficients in 3PN lowest mass ratio confirmed and numeric terms found to powers of ${e}^{2}$ post-Newtonian orders between 3.5PN 7PN. also show original work finding (nearly) arbitrarily...
We calculate the high-order post-Newtonian (PN) expansion of energy and angular momentum fluxes onto horizon a nonspinning black hole primary in eccentric-orbit extreme-mass-ratio inspirals. The first-order perturbation theory calculation uses Mathematica makes an analytic Regge-Wheeler-Zerilli functions using Mano-Suzuki-Takasugi formalism. absorption, or tidal heating torquing, is calculated to 18PN relative leading flux (i.e., 22PN order quadrupole at infinity). Each PN term function...
We discuss a procedure based on the use of multipole-moment expansions for matching numerical solutions gravitational-radiation field around compact source to linear analytic solutions. Gauge-invariant perturbation theory is used generate even- and odd-parity equations each spherical harmonic order $l$, $m$. This technique determines asymptotic wave forms, valid in local zone, from numerically evolved fields weak-field annular region surrounding isolated source. The separation form near-zone...
We consider tidal encounters between a white dwarf and an intermediate mass black hole. Both weak those at the threshold of disruption are modeled. The numerical code combines mesh-based hydrodynamics, spectral method solution self-gravity, general relativistic Fermi normal coordinate system that follows star debris. coordinates provide expansion hole field includes quadrupole higher multipole moments corrections. compute loss from occurs in encounters. Secondly, we carefully energy...
Extreme-mass-ratio inspirals (EMRIs), compact binaries with small mass-ratios $\ensuremath{\epsilon}\ensuremath{\ll}1$, will be important sources for low-frequency gravitational wave detectors. Almost all EMRIs evolve through transient orbital $r\ensuremath{\theta}$ resonances, which enhance or diminish their flux, thereby affecting the phase evolution of waveforms at $O({\ensuremath{\epsilon}}^{1/2})$ relative to leading order. While modeling local self-force (GSF) during resonances is...