Variation of Physical Constants  

In General > s.a. cosmology [future of the universe]; fine-structure constant; gravitational constant.
* History: Predicted by a number of theories, such as Kaluza-Klein; 1912, Einstein worked on variable-c gravity; 1937, Dirac proposed that could vary; 1955, Landau proposal; Bimetric theories predict a variation of c; 2009, Variations of constants of nature and acceleration of the universe could be related and governed by the evolution of a single field.
@ Reviews, status: Carilli pw(01)oct; Chiba gq/01-in; Martins PTRS(02)ap; Uzan ap/04-in; Olive & Qian PT(04)oct; Barrow & Webb SA(05)jun; Barrow PTRS(05)ap; news SFN(05)dec, space(06)jul; Dent AIP(07)hp/06; Flambaum IJMPA(07)-a0705; Melnikov G&C(07).
@ General references: Belinchón & Alfonso-Faus IJMPD(01)gq/04 [c = const]; Armendáriz-Picón PRD(02) [model]; Langacker IJMPA(04)hp/03-in [and extra dimensions]; Buchalter ap/04 [c, G, h, cosmology]; Ignatiev & Carson PLA(04) [e, , c: constraints]; MacGibbon ap/06, PRL(07)-a0706 [maximal rate allowed by second law of thermodynamics]; Flambaum AIP(06)phy; Martins ap/06-in [and dark energy]; Shaw gq/07 [possible seasonal changes]; Nea RPP(07) [comparisons of atomic frequency standards]; Fritzsch MPLA(08); Uzan a0907-in [general relativity extensions, cosmology].
@ Theory: Gleiser & Taylor PRD(85), PRD(86) [and Kaluza-Klein theory]; Barrow gq/97-ln; Dzuba et al PRL(99)phy/98; Vilenkin PRL(98)ht; Barrow & O'Toole MNRAS(01)ap/99 [in space]; Duff ht/02; Uzan RMP(03)hp/02; Rich AJP(03)oct-phy/02 [consequences]; Barrow ASS(03)gq/02-in; Vucetich ap/02-in [models]; Marion et al PRL(03)phy/02, Fischer et al PRL(04)phy/03 [lab experiment]; Dent et al PRD(08)-a0808; Flambaum PRL(09)-a0808 [critique of black-hole bounds], reply MacGibbon PRL(09)-a0810; Dent et al PRD(09)-a0812 [comparison of bounds]; Damour SSR-a0906-in [and the equivalence principle]; Flambaum & Berengut IJMPA(09); Nunes et al a0910-in [and cosmological acceleration].

Specific Constants > s.a. fine-structure constant; gravitational constant; particle types [e mass].
@ Variation of c: Tiwari in(80)gq/02; Ellman phy/98; Moffat ap/98-in; Coule MPLA(99); Albrecht ap/99-in; Manida gq/99; Clayton & Moffat PLB(99)ap/98, PLB(00), PLB(01)gq/01 [bimetric]; Carlip PRD(03)gq/02 [and black-hole thermodynamics]; Magueijo 03, RPP(03)ap; Ellis & Uzan AJP(05)mar-gq/03; Bel gq/03; Jafari & Shariati IJMPD(04)gq/03 [as reformulations of special relativity]; Ellis GRG(07)ap [requirements on theories], comments Magueijo & Moffat GRG(08)-a0705; Iorio GRG(09)-a0901 [planetary tests]; Izadi & Shojai CQG(09) [in extended-gravity theories]; > s.a. mach's principle.
@ Variation of c and G: Avelino & Martins PLB(99)ap [cosmology].
@ Variation of G and : Sharif & Kausar JKPS-a0911 [Bianchi III and Kantowski-Sachs cosmologies].
@ Varying-speed-of-light cosmology: Barrow PRD(99); Magueijo PRD(09)-a0807 [bimetric, primordial fluctuations]; Roshan et al PLB(09)-a0901 [solutions].
@ e/p mass ratio: Barshay & Kreyerhoff ap/07 [and a small cosmological constant]; Dent EPJST(08)-a0802-ln; Avelino PRD(08) [and ].
@ Coupling constants: Chamoun et al PLB(01) [strong coupling constant]; Kostelecky et al PRD(03) [and Lorentz violation]; Shaw & Barrow PRD(05)gq/04 [electroweak, quantum corrections]; Bambi & Drago APP(08)-a0711 [bounds from GRBs].
@ QCD parameters: Dmitriev & Flambaum PRD(03)ap/02 [(mq/QCD)]; Beane & Savage NPA(03)hp/02 [mq and nuclear physics].
@ Other constants: Bekenstein & Sagi PRD(08)-a0802 [G and Milgrom's a0 MOND parameter].
> Various theories: see brane cosmology; cosmological constant; dark matter; FRW models; gravitation ["variable lightcone"]; inflationary phenomenology; quantum cosmology; quantum geometrodynamics; relativistic cosmology; renormalization.

Bounds and Phenomenology > s.a. cosmic acceleration; modified lorentz symmetry; scalar-tensor theories.
* c, status: 2002, P Davies et al say examination of black holes and thermodynamics suggests that ·/ is due to c·.
* e/p mass ratio, status: 2006, Evidence from extreme UV lines of H for a 0.002% change over 12 Gyr, 3.5- level; 2007, Stronger upper bound of (–1 3) 10–16 yr–1 [from the inversion spectrum of ammonia]; 2008, Upper bound (–3.8 ± 5.6) 10–14 yr–1; 2009, Integrated / measured is (–7 8) 10–6.
@ General references: Sisterna & Vucetich PRD(90); Nordtvedt IJMPA(02)gq [and equivalence principle]; Olive et al PRD(02); Chengalur & Kanekar PRL(03)ap, Kanekar et al PRL(05) [using OH lines]; Rich AJP(03)oct-phy/02 [consequences]; Shaw & Barrow PRD(06)gq/05, PLB(06)gq/05, PRD(06)gq, Barrow & Shaw GRG(07)gq/06 [local effects]; Kanekar MPLA(08)-a0810 [techniques]; Landau et al PRD(08) [fine-structure constant, Higgs vacuum expectation value, electron mass].
@ Spatial variation: Barrow PRD(05)ap [cosmological bounds].
@ Dependence on gravitational potential: Dent PRL(08) [Eötvös-type bounds].
@ And nucleosynthesis: Ichikawa & Kawasaki PRD(02); MacDonald & Mullan PRD(09)-a0904 [strong force and anthropic principle].
@ And inflation: Martins ap/00-in; Chamoun et al IJMPD(07)ap/06 [strong coupling constant].
@ e/p mass ratio: Tzanavaris et al PRL(05)ap/04, MNRAS(07)ap/06 [21-cm + UV lines]; Barrow & Magueijo PRD(05)ap [cosmological constraints]; Ivanchik A&A(05)ap; Reinhold et al PRL(06) + pn(06)apr [evidence]; Chiba et al PRD(07); Flambaum & Kozlov PRL(07) + pw(07)jun; Shelkovnikov et al PRL(08) [lab constraint]; Murphy et al Sci(08)jun + sr(08)jun, King et al PRL(08)-a0807 [quasar spectra]; Thompson et al ApJ-a0907 [consistent with no change over 11.5 Gyr].
@ Variation of c: Albrecht & Magueijo PRD(99) [cosmology]; Bekenstein ap/03 [and lab spectroscopy].

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