Black-Hole Phenomenology  

In General > s.a. [gravitational phenomenology]; astronomy; sources of gravitational radiation.
* History: The idea of the existence of black holes seemed reasonable only after the discovery of pulsars in 1968.
* Status: 2005, Dozens of compact objects with masses > 3 Msun are known, and identified as black hole candidates.
Some of these have masses of 5–20 Msun and are found in X-ray binaries, the rest have Ms from a million to a billion Msun and are found in galactic nuclei; There is strong circumstantial evidence that many of them have event horizons.
* Parameters: The simplest black hole parameter to measure is the mass; We do not expect to find black holes with appreciable electric charge; A variety of methods are being tried to estimate their spin parameters, such as the polarization of X-rays emitted very close to the event horizon (in 1995 this was still not possible).
* Remark: The notion of event horizon is a global one; The local analogs are those of trapped surface, or isolated/dynamical horizon.
@ Reviews: Lasota SA(99)may; Rees in(03)ap/04; Cherepashchuk gq/05-in [search]; Narayan NJP(05)ap [astrophysics]; Bilic PoS(06)ap [especially X-ray binaries]; Müller PoS(06)ap/07 [evidence]; Romero a0805-ln; Czerny & Nikolajuk a0910-in [masses].
@ Falling in: Tammelo & Kask GRG(97) [passage through horizon]; Krasnikov G&C(08)-a0804 [pedagogical].
> Types of phenomena: see tests of general relativity with light and with orbits; gamma-ray astronomy; particle models; wormholes.

Stages in Black Hole Evolution > s.a. black-hole formation and radiation.
* Evaporation: After black-hole formation, in addition to possible growth by accretion of additional matter, the stages are (i) Balding, in which the black hole loses its hair and becomes stationary; (ii) Hawking radiation, in which the black hole shrinks; and (iii) Quantum gravity phase, about which we still don't know much.
* Hawking radiation: For small black holes, look for -rays over the background.
@ General references: Adams et al PLB(99) [effect of a cosmological constant on radiation]; Dalal & Griest PLB(00)ap [all eventually evaporate].
@ Hawking radiation: Stephens PLA(89); Rosu IJMPD(94)gq/96, NCB(93)gq/95, MPLA(93)gq/97, MPLA(98), G&C(01)gq/94.

Matter and Radiation near Black Holes > s.a. geodesics; maxwell and dirac fields in curved spacetime; neutrinos; Phantom Fields.
* Blandford-Znajek effect: The emission of relativistic charged particle jets by the magnetic field surrounding a black hole.
* Infalling particles: Particles with high orbital angular momentum will not fall into a black hole; For a Schwarzschild black hole, the maximum value of an infalling particle's is 4; For a Kerr black hole of angular momentum parameter a, an infalling particle's must satisfy –2 [1 + (1+a)1/2] < < +2 [1 + (1–a)1/2].
* Colliding particles: For two infalling particles of mass m that start from rest at infinity and collide near the surface of a Schwarzschild black hole, the maximum center-of-mass energy is 2·51/2 m [@ Baushev a0805]; Near a maximal (a = 1) Kerr black hole the maximum is 21/2 m [(2–2)/(1–2) + (1–2)/(2–2)]1/2.
* Infalling matter: The signature for radiation from a companion in a binary system, accretion disk, especially X-rays, includes no pulsating character, but possibly with modulation from disk and black-hole spin.
@ General references: Kuchiev PRD(04)gq/03, EPL(04)gq/03 [albedo]; de Diego et al GRG-ap/04 [electric charge].
@ Jet formation: Koide et al ap/99-in, ap/99/ApJL; de Felice & Zanotti GRG(00)ap/99; Gariel et al gq/07 [from Penrose process].
@ Accretion: Chakrabarti PRP(96)ap; Watarai & Mineshige PASJ-ap/03 [inner disk edge]; Das MNRAS(02)ap [transonic aspects], MNRAS(04)ap/03 [matter close to event horizon]; McKinney ap/05/ApJ, ap/05/ApJ [and jet formation]; news pw(08)apr [optical bursts]; > s.a. Penrose Diagram, perturbations.
@ Infalling matter: Tanaka et al Nat(95)jun [gravitational redshift]; Chakrabarti IJP-ap/98 [rev]; Biermann et al ap/02-in; Jacobson & Sitiriou PRL(09) [overspinning with a test body].
@ Binaries: Spallicci & Aoudia a0909 [stars around black holes, self-force]; > s.a. types of black holes.
@ Horizon evidence: Menou et al ap/97-in, gq/98-in; García et al ap/00/ApJ; Narayan & Heyl AIP(02)gq; Abramowicz et al A&A(02)ap [no proof]; Done & Gierlinski MNRAS(03)ap/02 [signature]; Narayan A&G(03)ap [no X-ray bursts]; Barbieri & Chapline a0812 [gamma-ray spectrum].
@ Scattering: Sánchez ht/97; Levin PRD(99)ap/98 [echo from chaotic scattering]; Mendoza et al Ent(09)gq/07 [Schwarzschild, absorption and reflection]; > s.a. Superradiance.
@ Lensing: Ohanian AJP(87)may; Virbhadra & Ellis PRD(00)ap/99 [by Schwarzschild]; Jackson PRD(01)gq [no hiding, and holography].

Black-Hole Detection and Observation > s.a. analogs [and mimickers]; black holes [view from the inside]; types of black holes.
* Status: There are many candidates, in a range of masses from stellar ones to supermassive ones in galactic cores, but no definitive evidence that they really are black holes; Although some people say that it is possible to observe effects arising from the presence of a horizon, the most convincing type may be the detection of the specific frequencies predicted for quasinormal modes, for example in ringdowns after mergers.
@ Appearance: Ames & Thorne ApJ(68); de Felice & Usseglio-Tomasset CQG(93) [orbiting]; Nemiroff AJP(93)jul-ap; Stuckey AJP(93)may [surrounding objects]; Marck CQG(96)gq/95; Zakharov et al gq/05-in; Vachaspati et al PRD(07)-gq/06 [from quantum collapse].

Other Effects and Properties > s.a. black-hole formation; kerr spacetime; quantum black holes; quantum cloning; spacetime subsets.
* Rotating black holes: According to a calculation by K Thorne, the maximum value of a allowed for a rotating (Kerr) black hole spun up by accreting matter is 0.998; This is a conservative bound, however, and more recent simulations suggest that the limit is at most 0.93.
* Energy extraction: Motivated by the search for viable models for the central engine of quasars, AGNs, and GRBs; One proposal is the Blandford–Znajek mechanism (see above).
* Retro-MACHOs: A black hole may act as a retro-lens which, if illuminated by a powerful light source, deflects light ray paths to large bending angles, allowing us to detect the black hole.
@ General references: Ruffini ap/98-in [electromagnetic particle production]; Dimopoulous & Landsberg PRL(01) + pn(01)sep [in the lab?].
@ As retro-MACHOs: Holz & Wheeler ApJ(02)ap [Schwarzschild]; De Paolis et al A&A(04)ap, Zakharov et al ap/04/A&A [Kerr].
@ Rotating black holes, frame dragging: Wex ap/99-in; Konno et al PRD(08)-a0807 [in Chern-Simons-modified gravity]; Herdeiro et al a0907 [back-reaction].
@ Accelerating black holes: Podolsky et al PRD(03)gq [radiation, in Anti-de Sitter]; > s.a. c-metric.
@ Energy extraction: Li & Paczynski ApJL(00)ap; Krolik ap/00-in [magnetic]; Frolov & Fursaev PRD(01)ht/00 [with cosmic strings]; Kim et al JCAP(03) [magnetic alignment]; Straumann AIP(08)-a0709 [rev]; Finster et al CMP(09) [rigorous treatment]; > s.a. Penrose Process.
@ Related topics: Jacobson PRD(98)ht/97 [near-extremal, decay]; Ghosh MNRAS(00)ap/99 [magnetosphere]; Hsu PLB(02) [parity]; Emparan et al JHEP(03) [in brane world]; Gott & Freedman ap/03/PRD [life preserver]; Bekenstein in(03)gq [preparing a desired black hole]; news pw(08)apr [blazars]; Poisson a0907 [tidal interactions]; Crane & Westmoreland a0908 [black-hole-powered spaceships]; > s.a. black-hole geometry [interior]; black-hole uniqueness; fine-structure constant; Gyromagnetic Ratio; Mass Inflation; variation of constants.

main page – abbreviations – journals – comments – other sites – acknowledgements
send feedback and suggestions to bombelli at olemiss.edu – modified 14 nov 2009