Causality in Quantum Theory  

In General > s.a. causality [as emergent]; quantum effects, locality and measurement; indefinite causality and causality violations.
* Idea: In the operator version it is built in via the unitarity of time evolution; Quantum non-locality is causal because it cannot be used to transfer classical information across spacelike intervals, and measurements of entangled systems cannot be used for superluminal signaling (not true in non-linear quantum mechanics); But see barrier transmission.
* Rem: Causal reversibility is related to the fact that observables form a real C*-algebra; Locality and separability then impose restrictions; Causally non-separable processes cannot be embedded in a well-defined global causal structure.
@ General references: Kraus FPL(89) [no action at a distance]; Stapp AJP(97)apr; Westmoreland & Schumacher qp/98; Mashkevich qp/98, qp/98; Cereceda FPL(00)qp [constraints and EPR]; Segev PRA(01) [phase-space formulation]; Simon et al PRL(01)qp [axioms]; Grove FP(02) [changing the past]; Belavkin RPP(02)qp [trajectories and information]; Palmer qp/05 [causal incompleteness and non-locality]; Pegg PLA(06) [arrow of time]; Evans et al BJPS(12)-a1001 [and spacelike action at a distance]; Hofmann a1005-proc [weak measurements, statistics and causality]; Zaopo a1110 [relativity of causal structure]; Gillis FP(11) [measurement and elementary interactions]; Oreshkov & Giarmatzi NJP(16)-a1506 [causality and causal separability, multipartite causal processes]; Diel a1604 [possibility of local causal models]; Eckstein & Miller PRA(17)-a1610 [evolution of wave packets]; Weilenmann & Colbeck Quant(20)-a1812 [in generalized probabilistic theories]; Eckstein et al PRA(20)-a1902.
@ Role of causality in quantum theory: Popescu & Rohrlich qp/97-proc [as axiom]; Wharton qp/03/PRA; Delphenich qp/04-conf; David PRL(11)-a1103 [role of causality and locality]; Kakushadze UJP-a1505 [rules based on causality]; Winter a1705; D'Ariano PTRS(18)-a1804 [conceptual]; Hofmann FP(20)-a2001 [causality as more fundamental than objective reality]; > s.a. quantum correlations.
@ And no-signaling constraints: Horodecki & Ramanathan nComm-a1611; Frembs & Döring a1910 [and contextuality].
@ Tests, causal inference: Ried et al nPhys(15)-a1406 [for quantum variables]; Chaves et al nPhys(18)-a1808 [violation of an instrumental test]; Fraser JCI(20)-a1902 [possible worlds framework]; Chiribella & Swati a2004 [quantum speedups].
@ Quantitative measures of causality: Jia a1801 [for general probabilistic theories]; Girolami PLA(20)-a1909, Escolà & Braun a2105 [quantifying causal influence].
@ Specific types of systems: Srikanth PLA(01) [entangled systems]; Kent PRD(99)gq/97 [time-neutral cosmologies]; Cotler et al JHEP(19)-a1811 [many-body systems, emergence of causal structure]; > s.a. causality in quantum field theory.
@ Related topics: Teufel et al PRA(97) [hidden variables]; Kent PRA(05)qp/02, Pienaar PhD-a1401 [and non-linear quantum mechanics]; Fitzsimons et al a1302 [pseudo-density matrix for spatial and temporal measurements]; Han & Choi a1307 [and probabilities]; Cavalcanti JPCS(16)-a1602 [proposals for a quantum theory of causation]; Allen et al PRX(17)-a1609 + Pienaar Phy(17) [quantum common causes, quantum version of Reichenbach's principle]; Thompson et al PRX(18)-a1712 [causal asymmetry in predictive modelling]; Kent PRS(18)-a1807 [causal quantum theory, implications]; Wechs et al NJP(19)-a1807 [causal non-separability]; Wakakuwa et al PRL(19)-a1810 [complexity of causal order structures].
> Related topics: see bell's theorem; Causal Models; contextuality; experiments in quantum theory [delayed-choice]; Lieb-Robinson Bounds; quantum collapse [and signaling]; Retrocausation.

Types of Causality > s.a. locality; path integrals.
* Abstract causal structures: A causal structure is a relationship between observed variables that restricts the set of possible correlations between them; Their study has become important for the development of quantum technologies, in particular quantum computing.
* Relativistic: Versions include Stochastic Einstein Locality, Reichenbach's Principle of Common Cause, and Bell's Local Causality.
* Information causality: A principle that places restrictions on physical processes, used in proposals for deriving quantum theory from information-theoretic considerations.
@ Abstract causal structures: Weilenmann & Colbeck Quant(18)-a1605, PRS(17)-a1709 [entropy-based approach]; Kissinger et al a1708 [and process terminality]; Milburn & Shrapnel Ent(18)-a1809 [causal interventions, physical basis].
@ Classical vs quantum causal structures: Vilasini & Colbeck PRR(20)-a1912 [entropic inequalities]; Vilasini a2102-PhD.
@ Information-theoretic constraints on correlations: Chaves et al nComm(15)-a1407; Weilenmann a1807-PhD.
@ Bell's local causality: Norsen AJP(11)-a0707; Seevink & Uffink in(11)-a1007 [sharp and clean mathematical formulation]; Ringbauer et al a1602 [test].
@ Information causality: Pawłowski et al Nat(09)oct-a0905; Barnum et al NJP(10)-a0909 [in general probabilistic theories]; Ahanj et al PRA(10) [and Hardy's non-locality]; Cavalcanti et al nComm(10)-a1008 [and local quantum correlations]; Gazi et al JPA(10) [and Hardy's correlations]; Al-Safi & Short PRA(11) [entropic and probabilistic perspective]; Beigi & Gohari a1111; Pawłowski & Scarani a1112 [rev]; Hsu PRA(12) [multipartite]; Yu & Lin a1301 [testing]; Pitalúa-García PRL(13); Zoka & Ahanj QS:MF(16)-a1510 [and quantum correlations]; Harremoës a2002 [from thermodynamic sufficiency]; > s.a. quantum correlations.

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