In General > s.a. localization; Reference Frame [accelerated]; Ultralocality.
* Locality principle: Roughly, a physical system can only interact with other systems in its immediate surroundings; A measurement on one particle cannot affect the properties of another particle before the appropriate light travel time; More generally, spacelike separated events cannot causally influence each other.
* Remark: The only strictly local theories are classical special-relativistic ones.
* Branch locality: An operational physical locality principle, similar to non-signaling but applicable to single systems; > s.a. Box World.
@ General references: Mashhoon PLA(90); d'Espagnat PLA(92); Hunter et al ed-98; Mashhoon in(03)gq [limitations]; Gisin qp/05-conf [history]; Doplicher JMP(10)-a0911-conf; Di Lorenzo a1105 [different definitions]; Dahlsten et al nComm(14)-a1206 [branch locality]; Weinstein a1211-FQXi [challenging the locality assumption]; van Hateren EPL(15)-a1505 [how non-locality can arise from strictly local interactions]; Robbin a2007 [David Bohm and Roger Penrose].
@ Consequences, uses of non-locality: Hoyle & Narlikar PRS(93) [infinities in field theory]; Bennett et al ht/95.
@ And fundamental physics: Oeckl a1412-PoS [approach based on locality and operationalism].
> Online resources: see Cornell Instrinsic Localized Modes site; Wikipedia page.
> Mathematical notions: see distributions.

In Classical Physics
* Formal role: It is important in special relativity (finite speed of propagation), but even more in general relativity (spacetime and laws are locally Minkowskian – see the principle of equivalence – and there is no distant parallelism), and similarly for gauge theories.
@ In field theory: Carati & Galgani NCB(99), Frisch BJPS(02) [non-locality in classical electrodynamics]; Fewster & Verch AHP(12)-a1109 [scalar field, dynamical locality]; Benini a1503-PhD [Abelian gauge theories]; > s.a. types of field theories.
@ In general relativity: Mashhoon in(01)gq/00, gq/01-proc; Chiao gq/03-proc [vs quantum mechanics].
@ Non-local theories: Ohira PhyA(07) [in time]; Mashhoon AdP(11)-a1006 [accelerated observers and necessity of non-locality].
> Non-local theories: see causality [action at a distance]; higher-order lagrangians; special relativity [non-local]; non-local field theories.
> Related topics: see huygens principle; temperature [local definitions]; wave phenomena.

In Quantum Physics > see locality in quantum mechanics and in quantum field theory.

Relative Locality > s.a. rainbow gravity.
* Idea: An approach to physics in which momentum space is taken as a primary object, and spacetime is emergent, motivated by the fact that we interact with the physical world by measuring energies and directions of incoming photons, rather than making measurements of spacetime itself; In this framework, momentum space is not flat; There is also a dual picture in which one gets spacetime non-commutativity from relative locality.
@ General references: Amelino-Camelia et al PRD(11)-a1101 [principle], PRD(11)-a1104, GRG(11)-a1106-GRF; Gubitosi & Mercati CQG(13)-a1106 [and the κ-Poincaré Hopf algebra]; Smolin talk(11)feb; Amelino-Camelia et al IJTP(12)-a1107 [transverse relative locality]; Carmona et al PRD(11)-a1107 [beyond special relativity]; Amelino-Camelia PRD(12)-a1110 [fate of Lorentz symmetry]; Smolin GRG(11); Loret et al JPCS(12)-a1207 [summary]; Amelino-Camelia et al PRD(12)-a1206 [and deformed Lorentz symmetry, in a curved spacetime]; Arraut a1301; Kowalski-Glikman & Rosati MPLA(13)-a1303 [in curved spacetime]; Banburski PRD(13)-a1305 [twisting loops and global momentum non-conservation]; Cianfrani et al PRD(14)-a1401 [generally-covariant formulation]; Amelino-Camelia et al PRD(15)-a1401 [causality and momentum conservation]; > s.a. minkowski spacetime; Observers; Soccer Ball Problem.
@ In specific models: Amelino-Camelia et al PLB(11)-a1102 [and speed of particles in κ-Minkowski spacetime]; Banburski & Freidel PRD(14)-a1308 [Snyder momentum space]; Ivetić & Mignemi IJMPD(18)-a1711 [Snyder model].
@ Related topics: Oliveira MS-a1110 [point-particle interactions]; Kowalski-Glikman & Szczachor a1212-proc [and the G → 0 limit of gravity]; Chen PRD(13) [causal loops]; Smolin a1311 [and twistor geometry].

main pageabbreviationsjournalscommentsother sitesacknowledgements
send feedback and suggestions to bombelli at olemiss.edu – modified 8 apr 2021