Numerical Simulation of Black-Hole Binaries

In General > s.a. models in numerical relativity; neutron stars; relativistic gravitating objects [two-body problem].
* Idea: Numerical relativity gives accurate waveforms used in matched-filtering to identify gravitational-wave signals; In practice one does not only use numerical results because it would be too expensive to produce all of the needed templates, so one also uses them to tune the theoretical waveforms generated from analytic models, that are much faster to compute; The result is a set of 'semi-analytic' models.
* Applicability: 2010, Extreme-mass-ratio cases are more difficult to handle numerically than equal-mass black holes (the code so far cannot run for more than about one orbit), although simpler in perturbation theory; For mass ratio q $$\ll$$ 1, the post-Newtonian formalism or black-hole perturbation theory are better; Improvements in the works include interfacing numerical techniques with semi-analytical ones, using sets of GPUs (graphics processing unitsm similar to video cards), statistical parameter reduction, and implementing techniques for parametric pdes.
* Supermassive: 2015, One puzzle is the "final parsec problem," the failure of theoretical models to predict what the final stages of a black hole merger look like or even how long the process might take, because the process depends on other matter surrounding the binary that might get a kick from it.
* Kicks, recoils: Numerical results have shown that asymmetric gravitational-wave emission provides a net kick to the black hole produced as a result of a merger; This kick gives it a speed of the order of 100s of km/s for non-spinning black holes, or ones with spins aligned or antialigned with their orbital angular momentum L, and speeds of up to 1000s of km/s for antiparallel spins at large angles with respect to L; This is enough to expel the merged black hole from a large galaxy.
* Dirty black holes: 2014, Results from modeling accretion disks around non-rotating black holes indicate that the ringdown phase of the coalescence of dirty black holes is dominated by the properties of the corresponding isolated black hole, especially at early times [& Vitor].
@ Reviews: Hinder CQG(10)-a1001 [status]; Marronetti & Tichy a1107-proc; Baumgarte & Shapiro PT(11)oct; Pfeiffer CQG(12)-a1203-proc; Sperhake CQG(15)-a1411; Duez & Zlochower RPP(18)-a1808.
@ General references: Baker et al PRD(02) [Lazarus project]; Damour et al PRD(02)gq; Khanna PRD(02)gq; Brügmann et al PRL(04)gq/03; Zlochower et al PRD(05)gq [4th-order accuracy]; Pretorius PRL(05)gq; Pretorius CQG(06)gq [generalized harmonic coordinates]; Hannam et al PRL(07)gq/06 [punctures]; Pollney et al PRD(11)-a0910 [high accuracy]; Loustó et al PRL(10)-a1001 [intermediate-mass-ratio regime]; Centrella et al RMP(10)-a1010 [and gravitational waves]; Meiron & Laor MNRAS(12)-a1110 [conservation-based method]; Damour et al PRL(12) [relation between binding energy and angular momentum]; Yo et al PRD(12)-a1205 [modified BSSN formulation, numerical stability]; Loustó & Zlochower PRD(13); Witek IJMPA(13)-a1308-ln [in higher dimensions]; Chu et al CQG(16) + Fong CQG+ [non-precessing]; Gerosa & Kesden PRD(16)-a1605 [spinning, with Python]; Healy et al CQG(17)-a1703 [RIT simulations catalog].
@ Initial data: Berti et al PRD(06) [eccentricity in data]; Dennison et al PRD(06) [approximate]; Reifenberger & Tichy PRD(12)-a1205 [alternative schemes]; Rácz a1605; Beyer et al a1903.
@ Effects: Boyle et al PRD(08)-a0804 [gravitational-wave energy loss]; Loustó & Healy PRL(15)-a1410 [spin flip-flop].

Collisions and Mergers
@ Reviews: Centrella AIP(06)ap, et al ARNPS(10)-a1010.
@ Collisions, head-on: Brandt et al gq/97-MG8; Anninos & Brandt PRL(98)gq; Dain PRD(01)gq; Witek et al PRD(10)-a1006 [in D dimensions]; Zilhão et al PRD(12)-a1205 [charged black holes]; Healy et al PRD(16)-a1506.
@ Collisions, other: Seidel gq/98-GR15; Brügmann IJMPD(99) [3+1]; Gómez et al PRD(01)gq/00; Husa et al gq/01-MG9; Gourgoulhon et al IJMPA(02)gq-conf [last orbit]; Khanna PRD(02)gq [parallel spins]; Campanelli et al PRD(06)gq; news pw(06)apr; Tichy & Marronetti PRD(08)-a0807 [final mass and spin]; Witek et al PRD(10)-a1004 [in a box]; Rezzolla et al PRL(10) ["antikicks"]; Santamaria et al PRD(10)-a1005 [and post-Newtonian waveforms]; Zlochower et al CQG(11)-a1011 [modeling recoils]; McWilliams CQG(11)-a1012 [merger simulations]; Berti et al PRD(12)-a1203 [effect of spin alignment on kicks]; Repetto et al MNRAS(12)-a1203 [stellar-black-hole kicks]; Sperhake et al PRL(13)-a1211 [high-energy, effect of black hole spins]; Zilhão et al PRD(14)-a1311 [oppositely-charged black holes]; Boyle et al a1904 [SXS Collaboration catalog].
@ Ringdowns: Kamaretsos et al PRL(12)-a1207 [encoded properties of the progenitor].
@ Supermassive, mergers: Bode et al ApJ(11)-a1101; Colpi SSR(14)-a1407.
@ Effects: Diener et al PRL(06)gq/05 [last orbit].