Black holes with synchronized or resonant scalar hair exhibit dynamical splitting in which the horizon is ejected from the bosonic cloud center in the very hairy regime.
A Fast Apparent-Horizon Finder for 3-Dimensional Cartesian Grids in Numerical Relativity
8 Pith papers cite this work. Polarity classification is still indexing.
abstract
In 3+1 numerical simulations of dynamic black hole spacetimes, it's useful to be able to find the apparent horizon(s) (AH) in each slice of a time evolution. A number of AH finders are available, but they often take many minutes to run, so they're too slow to be practically usable at each time step. Here I present a new AH finder,_AHFinderDirect_, which is very fast and accurate: at typical resolutions it takes only a few seconds to find an AH to $\sim 10^{-5} m$ accuracy on a GHz-class processor. I assume that an AH to be searched for is a Strahlk\"orper (star-shaped region) with respect to some local origin, and so parameterize the AH shape by $r = h(angle)$ for some single-valued function $h: S^2 \to \Re^+$. The AH equation then becomes a nonlinear elliptic PDE in $h$ on $S^2$, whose coefficients are algebraic functions of $g_{ij}$, $K_{ij}$, and the Cartesian-coordinate spatial derivatives of $g_{ij}$. I discretize $S^2$ using 6 angular patches (one each in the neighborhood of the $\pm x$, $\pm y$, and $\pm z$ axes) to avoid coordinate singularities, and finite difference the AH equation in the angular coordinates using 4th order finite differencing. I solve the resulting system of nonlinear algebraic equations (for $h$ at the angular grid points) by Newton's method, using a "symbolic differentiation" technique to compute the Jacobian matrix._AHFinderDirect_ is implemented as a thorn in the_Cactus_ computational toolkit, and is freely available by anonymous CVS checkout.
citation-role summary
citation-polarity summary
fields
gr-qc 8roles
background 4representative citing papers
Ultra-relativistic black hole flybys can radiate over 65% of their energy in gravitational waves via irregular waveforms caused by radiation trapping and lensing, without coalescence.
Numerical simulations of equal-mass boson-star mergers reveal larger waveform deviations from black-hole binaries in late inspiral and merger, plus odd multipole excitations for certain scalar-field phases, with some signals degenerate until IMR consistency tests are applied.
Numerical relativity in the decoupling limit reveals dynamical scalarization and spin-induced (de)scalarization during hyperbolic black hole encounters for both signs of the coupling.
Head-on black-hole mergers next to a companion show Doppler- and redshift-shifted ringdown, lensing magnification behind the lens, and delayed echo images, with only tentative signs of resonant mode excitation.
Numerical study of cusp formation on horizons in head-on non-spinning black hole mergers, with analysis of mass and multipole behavior at the cusp and a proposed phenomenological model.
Scattering black holes gain spin and mass by absorbing emitted gravitational radiation, with spin-up up to 0.3 and mass gain up to 15% in near-threshold encounters.
Bayesian parameter estimation with targeted eccentric numerical-relativity waveforms yields eccentricity estimates of e20 ≈ 0.2 for GW200208_22 and e10 ≈ 0.19 for GW190620, reinforcing the eccentric hypothesis.
citing papers explorer
-
Splitting the Gravitational Atom: Instabilities of Black Holes with Synchronized or Resonant Hair
Black holes with synchronized or resonant scalar hair exhibit dynamical splitting in which the horizon is ejected from the bosonic cloud center in the very hairy regime.
-
Trapping, Irregular Waveforms, and Efficient Radiation in Ultra-relativistic Black Hole Encounters
Ultra-relativistic black hole flybys can radiate over 65% of their energy in gravitational waves via irregular waveforms caused by radiation trapping and lensing, without coalescence.
-
Lessons from binary dynamics of inspiralling equal-mass boson-star mergers
Numerical simulations of equal-mass boson-star mergers reveal larger waveform deviations from black-hole binaries in late inspiral and merger, plus odd multipole excitations for certain scalar-field phases, with some signals degenerate until IMR consistency tests are applied.
-
Scalarization and descalarization in hyperbolic encounters of black holes
Numerical relativity in the decoupling limit reveals dynamical scalarization and spin-induced (de)scalarization during hyperbolic black hole encounters for both signs of the coupling.
-
Ringdown and lensing of triple systems
Head-on black-hole mergers next to a companion show Doppler- and redshift-shifted ringdown, lensing magnification behind the lens, and delayed echo images, with only tentative signs of resonant mode excitation.
-
Cusp Formation in Merging Black Hole Horizons
Numerical study of cusp formation on horizons in head-on non-spinning black hole mergers, with analysis of mass and multipole behavior at the cusp and a proposed phenomenological model.
-
Spin-up and mass-gain in hyperbolic encounters of spinning black holes
Scattering black holes gain spin and mass by absorbing emitted gravitational radiation, with spin-up up to 0.3 and mass gain up to 15% in near-threshold encounters.
-
Parameter Estimation with Targeted Eccentric Numerical-Relativity Simulations for GW200208_22 and GW190620
Bayesian parameter estimation with targeted eccentric numerical-relativity waveforms yields eccentricity estimates of e20 ≈ 0.2 for GW200208_22 and e10 ≈ 0.19 for GW190620, reinforcing the eccentric hypothesis.