Spacetime Singularities in Quantum Gravity  

Singularities in General > s.a. spacetime singularities [including modified gravity, probes] / quantum gravity and phenomenology.
@ References: Konkowski & Helliwell a1302-MG13, Helliwell & Konkowski PRD(13) [in conformally static spacetimes]; Czuchry et al PRD(17)-a1605 [do spikes in the approach to singularities persist?]; Bianchi & Haggard a1803-GRF [average of timelike singularities and the onset of quantum gravity]; Casadio et al a2102 [covariant approach].
blue bullet Related aspects of the theory: see cosmological phenomenology in quantum gravity; matter phenomenology [collapse].

Singularity Avoidance > s.a. models in canonical quantum gravity; spacetime singularities.
* History: Early work on Gowdy models using ADM variables was inconclusive; Work on FLRW models and black holes by Bojowald et al using connection variables, and by Husain & Winkler using metric variables, indicates that the singularity is avoided there; Conclusions however seem to be dependent on the approach to quantization.
@ General references: Wheeler GRG(77); Padmanabhan CQG(84); Smith & Bergmann PRD(86); Joshi NCB(90); Hosoya CQG(95); Brandenberger gq/95 [cosmological]; Hod gq/99; Gal'tsov gq/01-MG9 [behavior]; Konkowski & Helliwell in(03)gq/04, gq/04-MGX, et al gq/04-MGX [vs classical]; Mallios & Raptis gq/04 [abstract differential geometry]; Wilson gq/05-conf; Raptis IJTP(06); Bojowald AIP(07)gq [rev]; Haro & Elizalde JPA(09)-a0901 [in effective theory]; Nguyen & Parwani AIP(09)-a0902, GRG(09) [non-linear correction to Wheeler-DeWitt equation]; Arrechea et al a2010 [in semiclassical gravoty].
@ Censorship: Hod & Piran GRG(00)gq; Bonanno et al CQG(17)-a1610 [turning the classical singularity into a "whimper" singularity].
@ Near singularities: Joshi & Joshi CQG(88); Qadir & Siddiqui CQG(90)-a0801; Krori et al PLA(90); Mazumder IJTP(90) [cosmological]; Smailagic et al ht/03 [0-point length from T-duality]; Damour & Nicolai IJMPD(08)-a0705 [and maximally extended hyperbolic Kac-Moody algebra E10]; Stoica AP(14)-a1205 [degenerate metrics and small-scale dimensional reduction].
@ In different approaches: Callender & Weingard PLA(95) [Bohm theory]; Kofinas & Zarikas JCAP(15)-a1506 [asymptotic safety]; Esposito et al JPA(06)in [1-loop, euclidean]; Czuchry et al PRD(17)-a1605 [affine quantization]; Adéìféoba et al CQG(18)-a1808 [black-hole singularities, asymptotic safety]; Kuntz & Casadio a1911 [higher-derivative gravity]; > s.a. models in canonical quantum gravity; non-commutative gravity; string phenomenology.
@ Related topics: Bramson PRS(93) [particle model]; Russo PLB(94) [need non-trivial topologies]; Xiang & Shen MPLA(05) [and gup].

In Loop Quantum Gravity > s.a. FLRW quantum cosmology; pilot-wave quantum theory; quantum black holes.
@ General references: Bojowald PRL(05), et al PRL(05)gq [black holes]; Goswami et al PRL(06)gq/05 [scalar collapse, pw(06)jan]; Ashtekar & Bojowald CQG(06)gq/05 [Schwarzschild]; Bojowald CQG(06)gq/05 [degenerate metrics]; Modesto AHEP(08)gq/06 [Schwarzschild], ht/07-proc [black holes]; Böhmer & Vandersloot PRD(07)-a0709 [Schwarzschild spacetime]; Cailleteau et al PRL(08)-a0808 [various models and example of non-avoidance]; Varadarajan CQG(09)-a0812; Li & Zhu PRD(09)-a0812 [with tachyon field]; Ashtekar JPCS(09)-a0812 [rev]; Singh CQG(09)-a0901 [unified treatment of models]; Corichi & Singh PRD(09)-a0906 [geometric perspective]; DeBenedictis CJP(09)-a0907 [rev]; Tanaka et al PRD(11)-a1005 [and factor ordering]; Bojowald & Paily CQG(12)-a1206; Tehrani & Heydari IJTP(12)-a1207, AIP(12)-a1209 [charged black holes].
@ Lqc: de Haro JCAP(12)-a1207 [the big-rip singularity survives]; Corichi et al a1210-proc; Bamba et al JCAP(13)-a1211; Singh BASI-a1509 [rev]; Aresté Saló et al CQG(17)-a1612; Struyve sRep(17)-a1703; Saini & Singh CQG(19)-a1812 [in modified lqc]; Alonso-Serrano et al PRD(20)-a2001 [Bianchi I].

Specific Types of Models > s.a. 3D quantum gravity; bianchi I and minisuperspace models [other Bianchi models, singularity avoidance]; wormholes.
@ 3D models: Pitelli & Letelier PRD(08)-a0805 [BTZ black hole]; Unver & Gurtug PRD(10); Casals et al PLB(16)-a1605 [quantum dressing of a conical naked singularity].
@ FLRW models: Falciano et al PRD(12)-a1206 [Wheeler-DeWitt approach]; Bom et al PRD(14)-a1308 [consistent histories vs de Broglie-Bohm approaches]; Gielen & Menéndez-Pidal a2005 [resolution depends on the clock].
@ Other models: Calmet et al a2003 [spherically symmetric, quantum corrections].
@ Gravitational collapse: Hájíček NPB(01)ht/00, & Kiefer IJMPD(01)gq [spherical shell]; Modesto PRD(04)gq, CQG(06) [black holes]; Husain & Winkler CQG(05)gq/04, CJP(06) [spherical black holes + scalar]; Ziprick & Kunstatter PRD(09)-a0902 [massless scalar field]; Hossenfelder et al PRD(10)-a0912 [collapse and evaporation]; Casadio et al PLB(11)-a1008 [asymptotic safety]; Bambi et al EPJC(14)-a1306 [spherical collapse, bounce and expansion]; > s.a. gravitational collapse; phenomenology of geometry; renormalization [asymptotic safety]; modified electrodynamics.
blue bullet Pre-Big-Bang cosmology: see cmb anisotropy; loop quantum cosmology; string phenomenology.

main pageabbreviationsjournalscommentsother sitesacknowledgements
send feedback and suggestions to bombelli at – modified 28 feb 2021