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2000b]: ‘ReehSchlieder Defeats NewtonWigner: On Alternative Localization Schemes in Relativistic Quantum Field Theory’, submitted to Philosophy of Science
"... Many of the “counterintuitive ” features of relativistic quantum field theory have their formal root in the ReehSchlieder theorem, which in particular entails that local operations applied to the vacuum state can produce any state of the entire field. It is of great interest then that I.E. Segal an ..."
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Cited by 22 (5 self)
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Many of the “counterintuitive ” features of relativistic quantum field theory have their formal root in the ReehSchlieder theorem, which in particular entails that local operations applied to the vacuum state can produce any state of the entire field. It is of great interest then that I.E. Segal and, more recently, G. Fleming (in a paper entitled “ReehSchlieder meets NewtonWigner”) have proposed an alternative “NewtonWigner ” localization scheme that avoids the ReehSchlieder theorem. In this paper, I reconstruct the NewtonWigner localization scheme and clarify the limited extent to which it avoids the counterintuitive consequences of the ReehSchlieder theorem. I also argue that neither Segal nor Fleming have provided a coherent account of the physical meaning of NewtonWigner localization. 1
Entanglement and open systems in algebraic quantum field theory
 Studies in History and Philosophy of Modern Physics 32: 1–31
, 2001
"... Entanglement has long been the subject of discussion by philosophers of quantum theory, and has recently come to play an essential role for physicists in their development of quantum information theory. In this paper we show how the formalism of algebraic quantum "eld theory (AQFT) provides a rigoro ..."
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Cited by 21 (4 self)
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Entanglement has long been the subject of discussion by philosophers of quantum theory, and has recently come to play an essential role for physicists in their development of quantum information theory. In this paper we show how the formalism of algebraic quantum "eld theory (AQFT) provides a rigorous framework within which to analyse entanglement in the context of a fully relativistic formulation of quantum theory. What emerges from the analysis are new practical and theoretical limitations on an experimenter's ability to perform operations on a "eld in one spacetime region that can disentangle its state from the state of the "eld in other spacelikeseparated regions. These limitations show just how deeply entrenched entanglement is in relativistic quantum "eld theory, and yield a fresh perspective on the ways in which the theory di!ers conceptually from both standard nonrelativistic quantum theory and classical relativistic "eld theory. � 2001 Elsevier
Reichenbach's Common Cause Principle and Quantum Field Theory
, 1997
"... Reichenbach's principle of a probabilistic common cause of probabilistic correlations is formulated in terms of relativistic quantum field theory and the problem is raised whether correlations in relativistic quantum field theory between events represented by projections in local observable algebras ..."
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Cited by 12 (6 self)
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Reichenbach's principle of a probabilistic common cause of probabilistic correlations is formulated in terms of relativistic quantum field theory and the problem is raised whether correlations in relativistic quantum field theory between events represented by projections in local observable algebras A(V1) and A(V2) pertaining to spacelike separated spacetime regions V1 and V2 can be explained by finding a probabilistic common cause of the correlation in Reichenbach's sense. While this problem remains open, it is shown that if all superluminal correlations predicted by the vacuum state between events in A(V1) and A(V2) have a genuinely probabilistic common cause, then the local algebras A(V1) and A(V2) must be statistically independent in the sense of C*independence.
Local primitive causality and the common cause principle in quantum field theory, Found
 Phys
, 2002
"... If {A(V)} is a net of local von Neumann algebras satisfying standard axioms of algebraic relativistic quantum field theory and V 1 and V 2 are spacelike separated spacetime regions, then the system (A(V 1), A(V 2), f) is said to satisfy the Weak Reichenbach’s Common Cause Principle iff for every pai ..."
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Cited by 7 (5 self)
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If {A(V)} is a net of local von Neumann algebras satisfying standard axioms of algebraic relativistic quantum field theory and V 1 and V 2 are spacelike separated spacetime regions, then the system (A(V 1), A(V 2), f) is said to satisfy the Weak Reichenbach’s Common Cause Principle iff for every pair of projections A ¥ A(V 1), B ¥ A(V 2) correlated in the normal state f there exists a projection C belonging to a von Neumann algebra associated with a spacetime region V contained in the union of the backward light cones of V 1 and V 2 and disjoint from both V 1 and V 2, a projection having the properties of a Reichenbachian common cause of the correlation between A and B. It is shown that if the net has the local primitive causality property then every local system (A(V 1), A(V 2), f) with a locally normal and locally faithful state f and suitable bounded V 1 and V 2 satisfies the
Are Rindler Quanta Real? Inequivalent Particle Concepts in Quantum Field Theory
, 2000
"... Philosophical reflection on quantum field theory has tended to focus on how it revises our conception of what a particle is. However, there has been relatively little discussion of the threat to the “reality” of particles posed by the possibility of inequivalent quantizations of a classical field th ..."
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Cited by 7 (3 self)
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Philosophical reflection on quantum field theory has tended to focus on how it revises our conception of what a particle is. However, there has been relatively little discussion of the threat to the “reality” of particles posed by the possibility of inequivalent quantizations of a classical field theory, i.e., inequivalent representations of the algebra of observables of the field in terms of operators on a Hilbert space. The threat is that each representation embodies its own distinctive conception of what a particle is, and how a “particle ” will respond to a suitably operated detector. Our main goal is to clarify the subtle relationship between inequivalent representations of a field theory and their associated particle concepts. We also have a particular interest in the Minkowski versus Rindler quantizations of a free Boson field, because they respectively entail two radically different descriptions of the particle content of the field in the very same region of spacetime.
Massless particles, electromagnetism, and Rieffel induction
 Rev. Math. Phys
, 1995
"... The connection between spacetime covariant representations (obtained by inducing from the Lorentz group) and irreducible unitary representations (induced from Wigner’s little group) of the Poincaré group is reexamined in the massless case. In the situation relevant to physics, it is found that the ..."
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Cited by 5 (1 self)
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The connection between spacetime covariant representations (obtained by inducing from the Lorentz group) and irreducible unitary representations (induced from Wigner’s little group) of the Poincaré group is reexamined in the massless case. In the situation relevant to physics, it is found that these are related by MarsdenWeinstein reduction with respect to a gauge group. An analogous phenomenon is observed for classical massless relativistic particles. This symplectic reduction procedure can be (‘second’) quantized using a generalization of the Rieffel induction technique in operator algebra theory, which is carried through in detail for electromagnetism. Starting from the socalled Fermi representation of the field algebra generated by the free abelian gauge field, we construct a new (‘rigged’) sesquilinear form on the representation space, which is positive semidefinite, and given in terms of a Gaussian weak distribution (promeasure) on the gauge group (taken to be a Hilbert Lie group). This eventually constructs the algebra of observables of quantum electromagnetism (directly in its vacuum representation) as a representation of the socalled algebra of weak observables induced by the trivial representation of the gauge group.
Are prohibitions of superluminal causation by stochastic Einstein locality and by absence of Lewisian probabilistic counterfactual causation equivalent?
, 1993
"... Butterfield's (1992 ac) claim of the equivalence of absence of Lewisian probabilistic counterfactual causality (LC) to Hellman's Stochastic Einstein Locality (SEL) is questioned. Butterfield's assumption on which the proof of his claim is based would suce to prove that SEL implies absence of LC als ..."
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Cited by 1 (1 self)
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Butterfield's (1992 ac) claim of the equivalence of absence of Lewisian probabilistic counterfactual causality (LC) to Hellman's Stochastic Einstein Locality (SEL) is questioned. Butterfield's assumption on which the proof of his claim is based would suce to prove that SEL implies absence of LC also for appropriately given versions of these notions in algebraic quantum field theory  but the assumption is not an admissible one. The conclusion must be that the relation of SEL and absence of LC is open, and that they may be independent.
UNIFIED TREATMENT OF EPR AND BELL ARGUMENTS IN ALGEBRAIC QUANTUM FIELD THEORY
, 1998
"... A conjecture concerning vacuum correlations in axiomatic quantum field theory is proved. It is shown that this result can be applied both in the context of EPRtype experiments and Belltype experiments. Key words: unified EPR, Bell, algebraic QFT. 1. ..."
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Cited by 1 (0 self)
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A conjecture concerning vacuum correlations in axiomatic quantum field theory is proved. It is shown that this result can be applied both in the context of EPRtype experiments and Belltype experiments. Key words: unified EPR, Bell, algebraic QFT. 1.
Changing the Subject: Redei on Causal Dependence and Screening Off in Relativistic Quantum Field Theory
"... In a recent pair of articles (Redei 1996, 1997), Miklos Redei has taken enormous strides toward characterizing the conditions under which relativistic quantum field theory is a safe setting for the deployment of causal talk. Here, we challenge the adequacy of the accounts of causal dependence and sc ..."
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In a recent pair of articles (Redei 1996, 1997), Miklos Redei has taken enormous strides toward characterizing the conditions under which relativistic quantum field theory is a safe setting for the deployment of causal talk. Here, we challenge the adequacy of the accounts of causal dependence and screening off on which rests the relevance of Redei's theorems to the question of causal good behavior in the theory.
Remarks on Causality in
"... It is shown that the correlations predicted by relativistic quantum eld theory in locally normal states between projections in local von Neumann algebras A(V 1 ); A(V 2 ) associated with spacelike separated spacetime regions V 1 ; V 2 have a (Reichenbachian) common cause located in the union of the ..."
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It is shown that the correlations predicted by relativistic quantum eld theory in locally normal states between projections in local von Neumann algebras A(V 1 ); A(V 2 ) associated with spacelike separated spacetime regions V 1 ; V 2 have a (Reichenbachian) common cause located in the union of the backward light cones of V 1 and V 2 . Further comments on causality and independence in quantum eld theory are made.