Quantum Cosmology  

In General > s.a. cosmological effects of quantum gravity.
* And quantum mechanics: Quantum cosmology is becoming a new basis for quantum theory; One cannot follow the Copenhagen interpretation of quantum mechanics, because there are no classical observers here (measurement cannot have the same preferred role) and there is the problem of time; One possible way out is to take quantum mechanics seriously and include the observer (Everett, then extended by others); In some limit the Copenhagen interpretation then follows [for a criticism of this, @ Smolin pr(88)].
* Features: The topology of the universe is dynamical, especially before tP; Predicts fine tuning of constants of nature.

Models and Effects > s.a. FRW models; inflation; loop quantum cosmology [including bounces]; minisuperspace.
@ General references: Hervik CQG(01) [inhomogeneous]; Linde JCAP(04)ht [compact topologically non-trivial]; Benini & Montani CQG(07)gq/06 [inhomogeneous mixmaster]; Parisi et al a0706 [Einstein static universe stability].
@ Black-hole formation: Fang & Li PLB(86); Bousso & Hawking PRD(96)gq [during inflation]; Wu IJMPD(97)gq/98 [with Hartle-Hawking boundary conditions], MPLA(00)gq/99 [topological], GRG(01)gq/99 [BTZ], gq/98, MPLA(99)gq [in (A)dS]; > s.a. kerr spacetime.
> Other effects: see cmb; phenomenology [singularities].

Techniques and Related Topics > s.a. BRST; geometrodynamics; histories quantum mechanics; loop quantum cosmology; regge calculus.
@ WKB: Calzetta & González PRD(95)gq/94, Cornish & Shellard PRL(98)gq/97 [and chaos]; Embacher gq/96 [interpretation].
@ Unitarity: Lemos PRD(90) [and self-adjointness]; Linden & Perry NPB(91); Barvinsky PRP(93); Massar & Parentani PRD(99)gq/98.
@ Normalizability: Sarangi & Tye ht/05 [role of environment and decoherence].
@ Decoherence: Halliwell PRD(89); Padmanabhan PRD(89); Habib & Laflamme PRD(90) [Wigner function, WKB, coarse-graining]; Kiefer CQG(91) [scalar in de Sitter]; Laflamme & Louko PRD(91); Whelan PRD(98)gq/96, gq/97-in [conformally flat]; Castagnino IJTP(99)gq/00; > s.a. semiclassical general relativity and semiclassical quantum gravity.
@ Perturbations: Falciano & Pinto-Neto PRD(09)-a0810; > s.a. cosmological perturbations; phenomenology.
@ Conformal rotation: Hartle & Schleich in(87); Schleich PRD(89) [Bianchi I].
@ Measure on superspace: Barvinsky NPB(89); Gibbons & Turok PRD(08)ht/06.
@ Time: Feinberg & Peleg PRD(95)gq [and Wheeler-DeWitt operator]; Thibeault & Simeone IJMPD(07) [and two-component formalism].
@ Other topics: Horowitz PRD(85); Page IJTP(86) [size of universe]; D'Eath & Halliwell PRD(87) [fermions]; Fang & Mo PLB(87); Hu in(88)gq/95 [condensed-matter ideas]; Calzetta & Hu PRD(89) [phase-space formulation]; Vachaspati PLB(89); Farhi et al NPB(90); McGuigan PRD(90); Conradi & Zeh PLA(91); Calzetta & Kandus PRD(93) [observer dependence]; Laflamme CQG(93) [time-symmetric]; Halliwell & Ortz PRD(93)gq/92 [composition laws]; Mena CQG(94) [reality conditions]; Halliwell PRD(01)gq/00 [with detectors].
> Other: see boundary conditions; cosmological constant; effective quantum field theory; entropy; numerical relativity; spacetime topology.

Third Quantization > s.a. cosmological constant problem.
* Idea: A "second quantized" theory of , considered as a field on superspace.
* Criticism: The wave function is not measurable in any sense, so this appears not to make sense [@ Unruh & Wald PRD(89)].
@ References: McGuigan PRD(88); Fischler et al NPB(89); Giddings & Strominger NPB(89); Hosoya PRD(89); Strominger & Ellis PTRS(89); Cline NPB(90); Peleg CQG(91); Pimentel & Mora PLA(01)gq/00 [Brans-Dicke model].

Other References and Interpretation > s.a. lqc; multiverse; quantum gravity; path-integral quantum gravity; semiclassical general relativity.
* Interpretation: The main general issue is what to make of the quantum state if all we can ever observe is one universe; Other issues are that we–the observers– are located inside the universe–the system–, and the problem of time and observables.
@ First investigations: DeWitt PR(67); Wheeler in(68); Misner PR(69), in(70).
@ General references: Clarke PhSc(74); Greenberger FP(83) [model theory]; Narlikar & Padmanabhan PRP(83) [path integral]; Page PRD(86); Hartle in(88); Moss AIHP(88); Vilenkin PRD(88); Gibbons & Grishchuk NPB(89); Kiefer AP(91); Cavaglià gq/93 [and Kantowski-Sachs spacetime]; Page gq/95-in; Bojowald gq/03-in; Eakins gq/04-PhD [pure state]; Tetteh-Lartey a0709 [input from perturbative and non-perturbative approaches].
@ I: Boslough 85; Waldrop Sci(88)dec; Hawking 88; Novikov; Halliwell SA(91)dec; Bojowald SA(08)oct [bounce]; Hawking 08.
@ Books: Simeone 01 [path integral]; Montani et al 09.
@ Reviews: Hawking in(84), in(86), in(87); Hartle in(86); Halliwell IJMPA(90) [refs], in(92); Page in(91); Kiefer gq/93-in [demiclassical]; Grishchuk CQG(93); Atkatz AJP(94)jul; Vilenkin gq/93-in, PRD(94)gq, gq/95-in; Page gq/95-ln; Hartle in(96)gq, in(98)gq/97; Kiefer LNP(00)gq/99-in [conceptual]; Barvinsky gq/01-in; Wiltshire in(96)gq/01; Christodoulakis LNP(02)gq/01-in; Halliwell gq/02-in; Hartle gq/02-in; Page in(03)ht/06; Esposito gq/06-in; Kiefer & Sandhoefer a0804-in.
@ Lorentzian: Cline PLB(89); Farhi PLB(89); Duncan & Jensen NPB(89); Suen & Young PRD(89); Brown & Martinez PRD(90); Pesic NCB(93) [re Euclideanizing]; Altshuler & Barvinsky SPU(96).
@ Interpretation: Tipler PRP(86), in(86); Drees IJTP(87); Wada MPLA(88); Page in(91) [density matrix]; Wald in(91) [and time]; Parentani PRD(97)gq; Dzhunushaliev CQG(98) [Kolmogorov's algorithmic complexity]; Rubakov gq/99-in; Carter IJTP(04)ht-in [anthropic]; Longpré & Kreinovich IJTP(08) [algorithmic information theory]; > s.a. decoherence above, pilot-wave interpretation.
@ Other interpretations: Fink & Leschke FPL(00)qp; Page gq/00 [many-worlds]; > s.a. minisuperspace.
@ Philosophical aspects: Smith PhSc(88)mar; Smith & Weingard PhSc(90)dec; Craig BJPS(92), BJPS(93); Smith BJPS(94).
@ Related topics: Hartle in(91)gq/05; Sorkin IJTP(00)gq-in [and fundamental structure]; Krauss et al IJMPD(09)-a0810 [and late-time vacuum decay]; Page a0907 [state of the universe and observations].

In Generalized Theories > s.a. higher-order gravity; scalar-tensor; string phenomenology.
@ Brane world: Koyama & Soda PLB(00); Bouhmadi & González-Díaz PRD(02); Boyarsky et al PRL(05)gq/04 [in 5D Schwarzschild-AdS].
@ Higher dimensions: Halliwell NPB(86); Embacher G&C(95)gq/94; Mansouri & Nasseri PRD(99)gq [varying dimension]; Darabi et al CQG(00)gq [non-compact 5D Kaluza-Klein]; Peng et al IJTP(02)gq/01.
@ Signature transitions / fluctuations: Dereli et al CQG(93); Dzhunushaliev gq/02-in.
@ Supersymmetry: Macías et al IJMPA(93); D'Eath 96; Moniz IJMPA(96) [rev]; Obregón & Ramírez PRD(98); Macías et al PRD(98) [physical states]; Assaoui & Lhallabi PLB(01); D'Eath in(03)gq/05; Vargas Moniz GRG(06) [approaches].
@ Non-commutative: García-Compeán et al PRL(02)ht/01; Mena et al IJMPD(09)gq/07 [WKB-type approximation]; > s.a. non-commutative physics.
@ Other theories: Dragovich & Nesic G&C(99)gq/00 [p-adic, adelic]; Yurov & Yurov ht/05/PRD [varying c]; Ren et al PRD(07)-a0704 [FRW models with varying equation of state and cosmological constant]; Pedram & Jalalzadeh PLB(08)-a0712 [varying c].


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