Indefinite Causal Structures and Quantum Causality Violations  

Indefinite Causal Structures > s.a. causality [as emergent], in quantum field theory; axioms for quantum theory; regularization.
@ Reviews, introductions: Brukner nPhys(14)apr, PT(18)apr.
@ General references: Hardy gq/05, JPA(07)gq/06-in, a0804-in ["causaloids"]; Oreshkov et al nComm(12)-a1105; Ibnouhsein & Grinbaum PRA(15)-a1408, Ibnouhsein PhD(14)-a1510 [and information-theoretic reconstruction]; Baumeler & Wolf NJP(16)-a1511; Costa & Shrapnel NJP(16)-a1512 [framework for quantum causal modelling]; MacLean et al nComm(17)-a1606 [quantum-coherent mixtures]; Budroni et al PRA(16)-a1607 [distinguishability]; Araújo et al Quant(17)-a1611; Kissinger & Uijlen a1701 [categorical semantics]; Silva et al NJP(17)-a1701 [and multi-time quantum states]; Ried et al PRA(17)-a1707 [transitions between causal relations]; Abbott et al Quant(17)-a1708 [genuinely multipartite non-causal correlations]; Castro-Ruiz et al PRX(18)-a1710 [dynamics]; Guérin & Brukner NJP(18)-a1805 [causal reference frames and locality]; Pienaar a1806 [quantum causal models and QBism; causal relations are observer-dependent]; Paunković & Vojinović a1905 [causal orders and quantum circuits]; Milz et al a2008 [ontological status]; Selby et al a2008 [dynamics of quantum causal structures]; Goswami & Romero a2009 [rev, and experiments]; Baumann et al a2105 [Page-Wootters formulation]; > s.a. Causal Model; correlations [including out-of-time-order]; quantum computation.
@ Causal inequalities: Ho et al a1804 [violation in Minkowski space]; Purves & Short a2101 [they cannot be violated].
@ Correlations: Vilasini & Colbeck PRA(19)-a1907 [using Tsallis entropy].
@ Entanglement: Jia PRA(17)-a1707; Zych et al a1708, Rubino et al a1712 [entangled temporal orders].
@ Causally non-separable processes: Branciard SRep(16)-a1603; Feix et al NJP(16)-a1604 [processes admitting a causal model].
@ Superpositions of causal orders: Taddei et al a1903 [as an operational resource]; Pinzani & Gogioso a2003; Costa a2008 [no-go result].
@ And quantum communication: Ebler et al PRL(18)-a1711 [communication networks]; Salek et al a1809; Chiribella et al a1810 [perfect quantum communication]; Jia & Costa PRA(19)-a1901 [causal order as a resource].
@ Other phenomenology: Rubino et al SciAdv(17)-a1608 [experimentally implemented process without a definite causal order]; Perinotti in(17)-a1612 [and higher-order quantum computations]; Oreshkov Quant(19)-a1801 [local operations]; Goswami et al PRL(18)-a1803 [in a quantum switch]; news sn(18)aug [implementation]; Felce & Vedral a2003 [quantum refrigeration].

Causality Violations > s.a. hidden variables; locality; measurements [non-local]; quantum effects; Retrocausation.
* Superluminal communication: A number of proposals use quantum non-locality and the reduction process.
* Quantum mechanics with CTCs: A widely accepted theory was proposed by Deutsch; An alternative one was proposed by Lloyd et al.
@ General references: Cavalcanti PRX(18) [and non-locality, contextuality]; Shoshany a1907-ln.
@ Superluminal communication: Michalski qp/99-wd; Kuzmich et al PRL(01) [and quantum noise]; Yang qp/01; Griffiths PRA(02)qp [no problem]; Ferrero et al PRA(04) [and non-linearity]; Malikotsinas qp/04 [and entanglement]; Ferrero et al IJQI(05)qp [and non-linear evolution]; Panković et al qp/05 [Griffiths' bug shadow]; Bassi & Ghirardi IJTP(08)-a0711 [not possible with wave-function collapse]; Ghirardi & Romano JPA(12), a1305-wd [why some of the most challenging recent proposals cannot work]; Ghirardi in(13)-a1305 [exhaustive review of proposals to send faster-than-light signals]; Sokolovski & Akhmatskaya AP(13)-a1309 [rev]; Bassi & Hejazi EJP(15)-a1411 [no-superluminal-signaling implies linear evolutions].
@ Superluminal tunneling: Aharonov et al PRL(98)qp [and unstable states]; Chiao AIP(99)qp/98; Ghose & Samal PRE(01)qp/00 [and special relativity]; Muga et al PRA(02)qp [Hartman effect]; Sokolovski PRS(04)qp/03, PRA(10); > s.a. tunneling.
@ Other phenomenology: Bennett PRA(87), PRA(87) [evidence in Compton scattering]; Valentini PRL(88); Vaidman FP(91); Gray qp/98-wd [time machine]; Pegg in(01)qp/05 [and self-consistency]; Greenberger & Svozil in(02)qp/05 [beam-splitter model, paradox resolution], comment Wykes qp/05; Svetlichny IJTP(11)-a0902 [effective time travel]; news pt(19)sep [inexpensive crystal as quantum time machine]; > s.a. experiments [superluminal].
@ And unitarity: Anderson PRD(95)gq/94; Antonsen & Bormann IJTP(98)qp; Everett PRD(04)gq [many-worlds]; Cornalba & Costa PRD(06).
@ Quantum mechanics with closed timelike curves: Hartle PRD(94)gq/93 [and unitarity]; Fewster & Wells PRD(95)ht/94; Politzer PRD(94)gq; Rosenberg PRD(98)ht/97; Brun et al PRL(09)-a0811 [state distinguishability, cryptography]; DeJonghe et al PRD(10)-a0908 [discontinuous evolution]; Lloyd et al PRL(11)-a1005 + news sn(10)jul [time travel through post-selected teleportation]; Wallman & Bartlett FP(12)-a1005; Lloyd et al PRD(11)-a1007; Lee a1101 [finite state model]; Gedik a1201; Allen PRA(14)-a1401; Dunlap a1510 [metaphysics of Deutsch's approach]; Pinzani et al a1902 [categorical framework].
@ And experiments: Ringbauer et al nComm(14)-a1501 + news pw(15)feb [experimental simulation with photons]; Cocciaro et al JPCS(17)-a1701 [entanglement over kms].
> Related topics: see bell's theorem; phenomenology of entanglement [delayed-choice entanglement swapping]; quantum computation; quantum correlations; types of particles [fake particles and microcausality violations]; wave-function collapse.

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