Quantum-Gravity Phenomenology  

In General > s.a. approaches; effective theories; quantum gravity [including experiment, philosophy] and canonical quantum gravity; quantum spacetime.
* Idea: The identification of quantum properties of spacetime which might give rise to observably large effects.
* Types and examples: Theoretically, some predictions are geometric (like black hole area quantization, with ΔAmin ~ 4 ln2 lP2), others concern the behavior of matter (like photon propagation); Phenomenologically, some predict systematic shifts in observed quantities, others new fundamental uncertanties; 2015, The most promising context in which to look for effects may be cosmology, with imprints on the cmb.
* Scale: 1996, Bound is 10−19 m, from p-pbar collisions at Fermilab (no internal structure in quarks at that level), and p decay experiments have in effect probed smaller scales [@ news pn(96)dec]; 2008, Non-observation of small black holes produced by cosmic rays implies a model-independent lower bound of 488 GeV.
@ I / II: Amelino-Camelia pw(03)nov; Smolin PT(06)nov.
@ Reviews: Amelino-Camelia MPLA(02)gq-conf, a0806; Hossenfelder & Smolin PiC(10)-a0911-in; Hossenfelder a1010-conf; Barrau & Grain a1206-GRF; Girelli et al Sigma(12)-a1210 [lqg]; Amelino-Camelia LRR(13); Barrau & Grain a1410-ch [lqg]; Hossenfelder ed-18.
@ General references: Wheeler IJMPA(93); Salopek IJMPD(94); Smolin gq/95; Ashtekar PRL(96)gq [large effects]; Ahluwalia ChJP(97)gq [non-locality, free-fall, etc]; Amelino-Camelia MPLA(98)gq, LNP(00)gq/99-proc, Nat(01)gq, ap/02-ln [gamma and cosmic rays], et al APP(03)gq/02 [particle production]; Ashtekar mp/02-proc; Ahluwalia MPLA(02)gq-conf; Ng MPLA(03)gq, LNP(05)gq/04, NCB(05); Giulini et al ed-03; Amelino-Camelia GRG(04)ap/03 [in space], LNP(05)gq/04, et al AIP(05)gq [strategy]; Aloisio et al gq/04-MGX, NCB(05)ap-conf; Kimberly & Magueijo AIP(05)gq; Corichi & Sudarsky IJMPD(05)gq [new scheme]; Ahluwalia-Khalilova CQG(05)ht; Sudarsky IJMPD(05)gq; Smolin in(09)gq/06; Hossenfelder AIP(07)ht/06; Das & Vagenas PRL(08)-a0811 [universality of corrections]; Bonder & Sudarsky RPMP(09)-a0811, Bonder a1104-conf, a1204-conf [respecting Lorentz symmetry]; Liberati & Maccione JPCS(11)-a1105; Amelino-Camelia et al PRD(13) [physical characterization]; Bruneton a1308 [model-independent laws]; Fewster & Liberati GRG(14)-a1402 [GR20 report]; Marletto & Vedral a1704 [witnessing non-classicality indirectly]; Bonder a1704-proc [framework]; Loret et al a1805-MG14; Wüthrich a1902 [3 approaches].
@ Low-energy description: Ivanov a0706-conf; Nomura et al PLB(14)-a1304 [and complementarity]; Donoghue & Holstein JPG(15)-a1506 [from effective field theory].
@ Scales: Ne'eman PLA(94) [mass and localizability]; Dvali et al PRD(02) [as low as 10−3 eV]; Anchordoqui et al PRD(03)hp; Kazakov IJMPD(03)ht; Hong & Hsu PLB(04)hp/03 [brane world]; Han & Willenbrock PLB(05) [radiative corrections and new physics at 1018 GeV]; Meschini FS(07)gq/06 [Planck scale significance]; Calmet & Hsu PLB(08)-a0711, Calmet & Feliciangeli PRD(08)-a0806 [energy scale in 4D]; Dvali & Gómez PLB(09)-a0812 [theories with N species, and information]; Frampton CQG(09) [and black-hole formation]; Panković a0901 [from microscopic black holes]; Giddings AIP(09)-a0910 [beyond the Planck scale]; Borowiec et al EPL(10)-a0912 [constraints from κ-Minkowski spacetime]; Barceló et al FP(11)-a1002 [two distinct energy scales]; Atkins & Calmet EPJC(10)-a1005 [and unitarity]; Adler AJP(10)sep [elementary arguments]; Basilakos et al JCAP(10)-a1009 [effects on the Planck era]; Adler a1110 [gravitational fine-structure constant]; Olmo JCAP(11) [invariant and universal length scale]; Nozari et al EPL(15)-a1512 [bounds from QCD]; Arzano & Calcagni a1604 [GW150914, gravity waves]; Chang et al a1605-GRF; Battista a1606-PhD [low-energy and high-energy limits]; Singh a1704-GRF [Compton-Schwarzschild length]; Bonder et al a1704 [polymer scale and GRBs]; Faraoni AJP(17)nov-a1705 [heuristic derivations of the Planck scale]; Bodendorfer et al a1902 [the Hamiltonian as a polymerisation parameter]; > s.a. Chandrasekhar Limit; GUTs.
@ In modified theories: Arzano et al PRD(15)-a1412 [with anti-de Sitter momentum space].
@ Against the idea: Mohrhoff MPLA(02)qp [quantum-gravity phenomenology = "contradiction in terms", only hep cutoff].

Spacetime Measurements and Minimal Length > s.a. DSR; modified lorentz symmetry.
* Idea: Quantum uncertainties in the metric limit spacetime measurements, modify uncertainty relations and, from hoop-conjecture-type arguments, have often been used to argue for the existence of a fundamental minimal length (for example, the time of an event cannot be determined with accuracy better than σt /t = a0 (tP/t)a, for some a0, a ~ 1); The latter in turn has been used as motivation for modified dispersion relations, or a modified action of the Lorentz group (as in DSR).
@ Limitations: Salecker & Wigner PR(58); in Misner et al 73, 1190ff; Padmanabhan CQG(87); Mashhoon PLA(90); Wheeler PRD(90); Schön gq/93; Amelino-Camelia MPLA(94)gq/96, MPLA(96)gq, PLB(97)gq/96, PLB(00)gq/99; Ng & Van Dam MPLA(94); Jaekel & Reynaud PLA(94)qp/98, QSO(95)qp; Baez & Olson CQG(02)gq, comment Ng & van Dam CQG(03)gq/02; Calmet et al PRL(04)ht, IJMPD(05)ht-GRF; Lloyd qp/05-wd [covariant, from computation]; Galán & Mena PRD(05)gq [from DSR]; Calmet EPJC(08)ht/07-proc, MPLA(07)-a0704-proc; Amelino-Camelia & Stachel GRG(09)-a0710; Requardt a0807 [closer inspection]; Hossenfelder CQG(12)-a1205, comment Doplicher et al a1206; Lloyd a1206 [quantum geometric limit]; Burderi et al PRD(16)-a1603 [limits on time measurements]; Maziashvili a1908.
@ Minimal length: Heisenberg ZP(43); Garay IJMPA(95)gq/94; Hinrichsen & Kempf JMP(96)ht/95; Padmanabhan PRL(97)ht/96 [duality]; Amelino-Camelia AIP(01)gq; Chang ht/04-conf; Hossenfelder MPLA(04)hp [and large extra dimensions]; Ahluwalia-Khalilova IJMPD(05)ht [from stabilized Poincaré-Heisenberg algebra]; Hossenfelder CQG(06)ht/05 [consistency of approaches]; Schiller IJTP(06); Maziashvili hp/06; Klinkhamer JETPL(07)gq [different from Planck length]; Kempf PRL(09)-a0908 [natural ultraviolet cutoff]; Martinetti et al RVMP(12)-a1106 [in non-commutative geometry]; Sprenger et al EJP(12)-a1202 [intro]; Hossenfelder LRR(13)-a1203; Kothawala PRD(13)-a1307; > s.a. asymptotic safety; Hausdorff Dimension; effects on matter; poincaré group [deformed]; world function.
@ Minimal length and string theory: Veneziano EPL(86); Gross & Mende NPB(88); Amati et al PLB(89); Konishi et al PLB(90); Aspinwall NPB(94)ht [strings].
@ Minimal length and quantum field theory: Brustein et al PRD(02)ht/00; Lieu ApJL(02)ap [hep]; Hossenfelder PRD(06)ht [interpretation]; Campo a1004 [problems with causality and/or unitarity]; Basu & Mattingly PRD(10)-a1006 [closer look at handwaving arguments]; Cunliff CQG(12)-a1201 [conformal fluctuations and lower bound on proper lengths]; Doplicher et al JGP(13)-a1201 [event localization in semiclassical gravity]; > s.a. types of quantum field theories.
@ Lorentz invariance: Rovelli & Speziale PRD(03)gq, Livine & Oriti JHEP(04)gq [discrete]; Alfaro et al PRD(04) [lqg, variables].
@ Minimum time: Itzhaki PLB(94)ht; Barbero et al PRD(04)gq/03 [non-perturbative model]; El Dahab & Tawfik CJP(14)-a1401.
@ Simultaneity: Kok et al qp/02 [distributed entanglement].

Other Effects and Applications
> Specific issues and topics: see Anyons; causality violations; constants; Correspondence Principle; deformed and entropic uncertainty relations; entanglement and gravity; entanglement phenomenology; entropy bound; neutrinos [masses]; observables; parity [violation]; Planck's Constant.
> Experiments: see SAGE.
> In related areas: see cosmology [including cosmological singularities]; gravitation and astrophysics; photons; particle properties and matter in general; quantum computing; spacetime foam; spacetime geometry [including metric fluctuations, gravitational collapse, other singularities, volume and chaos].

main pageabbreviationsjournalscommentsother sitesacknowledgements
send feedback and suggestions to bombelli at olemiss.edu – modified 26 aug 2019