Measurement in Quantum Theory

In General > s.a. observables; experiments in physics.
* Measurement problem: Understanding the reduction of the wave packet of a microsystem and the specification of its quantum state (wave-function collapse) by a macroscopic measuring instrument.
* Approaches: Two types of approaches are (a) The collapse of the wave function, as [i] a non-linear physical process by which at the time of measurement the wave-function collapses into one of the possible alternatives, which requires that quantum mechanics to be modified from its present form or [ii] as an effective process due to decoherence; and (b) The many-worlds interpretation, which asserts that at the time of measurement the Universe splits into many branches, one for every possible alternative, and does not require any modification of quantum
mechanics; The various branches do not interfere with each other because of decoherence.
* Formalism: Measurements can be represented by positive operator-valued measures.
* History: V Fock and S Ludwig thought that apparata should be treated classically, but then the probabilistic outcome of experiments cannot be described; J Bell advocated using the word "experiment" instead of "measurement".
* Landau-Lifshitz conjecture: Relationship with second law of thermodynamics.
* Issues: Which measurements can be consistently performed? Some lead to acausal properties [@ Sorkin in(90)].

And Relativity > s.a. causality; collapse of the wave function; relativistic quantum mechanics; spacetime; spacetime topology.
@ Lorentz invariance: Bloch PR(67); Pitowsky PLA(91) [observer dependence of predictions]; Droz-Vincent FP(95); Mensky & von Borzeszkowski PLA(95)qp/00 [measurement of electromagnetic field]; Marolf & Rovelli PRD(02)gq [detector and localization].
@ And causality: Zanchini & Barletta NCB(91); Moffat gq/97; Svetlichny FP(03) [detectors and collapse]; Gambini & Porto NJP(03)qp/02.
@ Quantum gravity: Menskii in(85); Ahluwalia PLB(94)gq/93; González-Díaz IJTP(98)qp/97; Anandan FP(99)gq/98; Percival PRS(00)qp/98 [cosmic "measurement field"]; Hadley IJTP(99) [effect of geons].

In Quantum Field Theory > s.a. QED.
@ General references: in Heitler 54; Aharonov et al PRD(86); Sorkin gq/93-in [impossible measurements]; Danos & Kieu IJMPE(99)qp/97; Álvarez-Estrada & Sánchez-Gómez PLA(99)qp/98 [decay, no Zeno effect]; Gambini & Porto NJP(02)qp [realistic interpretation]; Rubin a0909 [in many-worlds interpretation].
@ Electromagnetic field: Bohr & Rosenfeld KDVS(33), PR(50); Menskii TMP(89); von Borzeszkowski & Mensky PLA(94)qp/00.
@ And quantum gravity: Gadiyar ht/01 [and volume quantization]; von Borzeszkowski et al FP(02); Oeckl CQG(03).

Special Topics > s.a. arrow of time; quantum states; realism; time in quantum mechanics; types of quantum measurement.
@ Intrinsic measurement theory: Zurek PRD(81), PRD(82); Deutsch IJTP(85); Allahverdyan et al qp/04-in [full hamiltonian model].
@ And entanglement: Busch IJTP(03).
@ And observers: Singh & Whitaker AJP(82)oct [and decays]; Albert PLA(83) [self-description]; Mould FP(95) ["inside" observers]; Rosenblum & Kuttner FP(02); Thaheld qp/07.
@ And algebras / logic: Pulmannová JMP(94); Lehmann et al IJTP(06)qp/05.
@ And consciousness: Squires qp/96; d'Espagnat FP(05)qp/04.
@ Phase-space formulation: Dragoman PS(05)qp/04; Carmeli et al JPA(04)qp.
@ Post-measurement state: Audretsch et al PRA(03)qp/02; Laura & Vanni IJTP(08) [using conditional probabilities].
@ Reversibility: Peres AJP(74)oct; Peres FP(88); Svozil in(98)-a0904 [and reversible automata]; van Enk & Raymer a0901/AJP [and reliability].
@ Other topics: Landsman IJMPA(91) [and superselection sectors]; Mallah qp/02 [and conservation laws]; Busch et al PLA(04) [noise and disturbance]; Lahti et al qp/04 [full observable from first and second moments]; Allahverdyan et al cm/04 [exactly solvable model]; Gudder RPMP(05) [additive and product structure]; Ji et al PRL(06) [distance measures]; Janssens qp/06 [inequalities]; Mermin QIP(06)qp, comment Ghirardi FP(08)-a0806, reply Mermin a0808 [and quantum computing]; > s.a. Beable, information.

References > s.a. decoherence; entropy; foundations; histories formulations; modified quantum mechanics; wave-function collapse.
@ Non-technical: Dirac SA(63)may; Bell PW(90)aug; Gottfried PW(91)oct; Christian MR(96)qp/97.
@ Early papers: Furry PR(36), PR(36).
@ General: London & Bauer 39; Feyerabend ZP(57); Durand PhSc(60)apr; Daneri et al NP(62); Margenau AP(63); Shimony AJP(63)oct, comment Hack AJP(64)nov; Wigner AJP(63)jan, in(71); Rosenfeld PTPS(65); d'Espagnat ed-71; Prosperi in(71); Maxwell AJP(72)oct, AJP(73)aug; Margenau & Park FP(73); Reece IJTP(73); Peres PRD(80); Wheeler & Zurek ed-83; Walls et al PRD(85) [analysis]; Peres AJP(86)aug; Greenberger ed-87; Home & Whitaker PLA(88); Leggett FP(88); Maki PTP(88), PTP(89); Dicke FP(89); Peres PLA(90) [incompatible results]; Nakazato & Pascazio PLA(91); Busch et al 91; Braginsky et al 92; Mensky 92; Schulman AP(91), 92; Belavkin FP(94)qp/05 [without projection postulate]; Busch & Lahti FP(96)qp [history and models]; Ozawa in(01)qp [axiomatic]; Gurvitz QIP(03)qp/02 [classical apparatus]; Rajeev qp/03-in [errors]; Sewell RPMP(05) [mathematical structure]; Griffiths qp/06 [quantum mechanics without measurements]; Singh a0711-in [quantum gravity favors wave-function-collapse interpretation]; Lundeen et al Nat-a0807 [observables and detectors].
@ The problem: Fine PRD(70), PRD(72), Brown FP(86) [insolubility]; Moldauer PRD(72); Bassi & Ghirardi PLA(00); Grübl PLA(03)qp/02 [impure states]; Dass qp/05-in [intro, and decoherence]; Wallace a0712-in [rev]; Bub & Pitowsky in(09)-a0712 [as pseudo-problem].
@ Measurement vs state preparation: Margenau PhSc(58)jan; Jauch HPA(64); Park & Band FP(92).
@ Measurement vs dynamics: Aharonov & Reznik qp/97; Nielsen PRL(97)qp; Allahverdyan et al cm/03-in [model].
@ Algebraic approach: Maki PTP(90); Slavnov a0810.
@ Approaches: Albertson PR(6) [measurement operator]; Peres & Rosen AP(64) [classical test-body model]; Bohm & Hiley FP(84) [quantum potential]; d'Espagnat PLA(87) [and consistent histories]; Steane JPA(90); Hofer qp/00-in; Marsh PRA(01) [system-apparatus density matrix]; Balduz qp/01 [theory of observers]; Loubenets JPA(01)qp [quantum stochastic approach]; Dumitru qp/02; Adler SHPMP(03) [and decoherence]; Sokolovski & Sala Mayato PRA(05) [sum-over-histories view]; Sewell RPMP(05)mp; Allahverdyan et al qp/05 [as phase transition]; Belavkin qp/05-in [dynamical solution]; Sewell a0710-in [solution within standard formalism]; Jaroszkiewicz a0812 [dynamical theory]; Gambini et al a0905 [quantum gravity and undecidability]; Doplicher a0908 [model in local quantum theory].
@ And other interpretations: McKnight PhSc(58)jul; Zeh FP(70); Mittelstaedt 98; Bene & Dieks qp/01 [modal]; > s.a. pilot-wave interpretation.
@ More philosophical: McKnight PhSc(57)oct; Bitbol PhSc(88)sep; Mohrhoff qp/01 [and weak objectivity]; French SHPMP(02) [history].

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