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58
Physical versus Computational Complementarity I
, 1996
"... The dichotomy between endophysical/intrinsic and exophysical/extrinsic perception concerns the question of how a model  mathematical, logical, computational  universe is perceived from inside or from outside, [71, 65, 66, 59, 60, 68, 67]. This distinction goes back in time at least to Archimedes, ..."
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Cited by 20 (19 self)
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The dichotomy between endophysical/intrinsic and exophysical/extrinsic perception concerns the question of how a model  mathematical, logical, computational  universe is perceived from inside or from outside, [71, 65, 66, 59, 60, 68, 67]. This distinction goes back in time at least to Archimedes, reported to have asked for a point outside the world from which one could move the earth. An exophysical perception is realized when the system is laid out and the experimenter peeps at the relevant features without changing the system. The information flows on a oneway road: from the system to the experimenter. An endophysical perception can be realized when the experimenter is part of the system under observation. In such a case one has a twoway informational flow; measurements and entities measured are interchangeable and any attempt to distinguish between them ends up as a convention. The general conception dominating the sciences is that the physical universe is perceivable ...
Dust as a standard of space and time in canonical quantum gravity. Phys. Rev. D51
, 1995
"... The coupling of the metric to an incoherent dust introduces into spacetime a privileged dynamical reference frame and time foliation. The comoving coordinates of the dust particles and the proper time along the dust worldlines become canonical coordinates in the phase space of the system. The Hamilt ..."
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Cited by 11 (0 self)
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The coupling of the metric to an incoherent dust introduces into spacetime a privileged dynamical reference frame and time foliation. The comoving coordinates of the dust particles and the proper time along the dust worldlines become canonical coordinates in the phase space of the system. The Hamiltonian constraint can be resolved with respect to the momentum that is canonically conjugate to the dust time. Imposition of the resolved constraint as an operator restriction on the quantum states yields a functional Schrödinger equation. The ensuing Hamiltonian density has an extraordinary feature: it depends only on the geometric variables, not on the dust coordinates or time. This has three important consequences. First, the functional Schrödinger equation can be solved by separating the dust time from the geometric variables. Second, the Hamiltonian densities strongly commute and therefore can be simultaneously defined by spectral analysis. Third, the standard constraint system of vacuum gravity is cast into a form in which it generates a true Lie algebra. The particles of dust introduce into space a privileged system of coordinates that allows the supermomentum constraint to be solved explicitly. The Schrödinger equation yields a conserved inner product that can be written in terms of either the instantaneous state functionals or the solutions of constraints. Gravitational observables admit a similar dual representation. Examples of observables are given, though neither the intrinsic metric nor the extrinsic curvature are observables. Disregarding the standard factor–ordering difficulties, the introduction of dust provides a satisfactory phenomenological approach to the problem of time in canonical quantum gravity. Typeset using REVTEX 1 I.
The Sasaki hook is not a [static] implicative connective but induces a backward [in time] dynamic one that assigns causes
 Int. Journ. of Theor. Physics
"... In this paper we argue that the Sasaki adjunction, which formally encodes the logicality that different authors tried to attach to the Sasaki hook as a ‘quantum implicative connective’, has a fundamental dynamic nature and encodes the socalled ‘causal duality ’ (Coecke, Moore and Stubbe 2001) for t ..."
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Cited by 8 (3 self)
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In this paper we argue that the Sasaki adjunction, which formally encodes the logicality that different authors tried to attach to the Sasaki hook as a ‘quantum implicative connective’, has a fundamental dynamic nature and encodes the socalled ‘causal duality ’ (Coecke, Moore and Stubbe 2001) for the particular case of a quantum measurement with a projector as corresponding selfadjoint operator. In particular: The action of the Sasaki hook (a S → −) for fixed antecedent a assigns to some property “the weakest cause before the measurement of actuality of that property after the measurement”, i.e. (a S → b) is the weakest property that guarantees actuality of b after performing the measurement represented by the projector that has the ‘subspace a ’ as eigenstates for eigenvalue 1, say, the measurement that ‘tests ’ a. From this we conclude that the logicality attributable to quantum systems contains a fundamentally dynamic ingredient: Causal duality actually provides a new dynamic interpretation of orthomodularity. We also reconsider the status of the Sasaki hook within ‘dynamic (operational) quantum logic ’ (DOQL), what leads us to the claim made in the title of this paper. More explicitly, although (as many argued in the past) the Sasaki hook should not be seen as an implicative hook, the formal motivation that persuaded others to do so, i.e. the Sasaki adjunction, does have a physical
The timeenergy uncertainty relation
 Time in Quantum Mechanics, chapter 3
, 2002
"... The time energy uncertainty relation ∆T ∆E ≥ 1 � (1) 2 ..."
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Cited by 7 (0 self)
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The time energy uncertainty relation ∆T ∆E ≥ 1 � (1) 2
PositiveOperatorValued Time Observable in Quantum Mechanics
, 2008
"... We examine the longstanding problem of introducing a time observable in Quantum Mechanics; using the formalism of positiveoperatorvalued measures we show how to define such an observable in a natural way and we discuss some consequences. Pacs: 03.65.Bz Quantum theory; UTF390. ..."
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We examine the longstanding problem of introducing a time observable in Quantum Mechanics; using the formalism of positiveoperatorvalued measures we show how to define such an observable in a natural way and we discuss some consequences. Pacs: 03.65.Bz Quantum theory; UTF390.
NonBoolean Descriptions for MindMatter Problems
"... A framework for the mindmatter problem in a holistic universe which has no parts is outlined. The conceptual structure of modern quantum theory suggests to use complementary Boolean descriptions as elements for a more comprehensive nonBoolean description of a world without an apriorigiven mindmat ..."
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Cited by 6 (0 self)
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A framework for the mindmatter problem in a holistic universe which has no parts is outlined. The conceptual structure of modern quantum theory suggests to use complementary Boolean descriptions as elements for a more comprehensive nonBoolean description of a world without an apriorigiven mindmatter distinction. Such a description in terms of a locally Boolean but globally nonBoolean structure makes allowance for the fact that Boolean descriptions play a privileged role in science. If we accept the insight that there are no ultimate building blocks, the existence of holistic correlations between contextually chosen parts is a natural consequence. The main problem of a genuinely nonBoolean description is to find an appropriate partition of the universe of discourse. If we adopt the idea that all fundamental laws of physics are invariant under time translations, then we can consider a partition of the world into a tenseless and a tensed domain. In the sense of a regulative principle, the material domain is defined as the tenseless domain with its homogeneous time. The tensed domain contains the mental domain with a tensed time characterized by a privileged position, the Now. Since this partition refers to two complementary descriptions which are not given apriori,wehavetoexpectcorrelations between these two domains. In physics it corresponds to Newton’s separation of universal laws of nature and contingent initial conditions. Both descriptions have a nonBoolean structure and can be encompassed into a single nonBoolean description. Tensed and tenseless time can be synchronized by holistic correlations. 1.
Localization of Events in SpaceTime
, 1997
"... The present paper deals with the quantum coordinates of an event in spacetime, individuated by a quantum object. It is known that these observables cannot be described by selfadjoint operators or by the corresponding spectral projectionvalued measure. We describe them by means of a positiveopera ..."
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Cited by 5 (2 self)
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The present paper deals with the quantum coordinates of an event in spacetime, individuated by a quantum object. It is known that these observables cannot be described by selfadjoint operators or by the corresponding spectral projectionvalued measure. We describe them by means of a positiveoperatorvalued (POV) measure in the Minkowski spacetime, satisfying a suitable covariance condition with respect to the Poincaré group. This POV measure determines the probability that a measurement of the coordinates of the event gives results belonging to a given set in spacetime. We show that this measure must vanish on the vacuum and the oneparticle states, which cannot define any event. We give a general expression for the Poincaré covariant POV measures. We define the baricentric events, which lie on the worldline of the centreofmass, and we find a simple expression for the average values of their coordinates. Finally, we discuss the
On the Quantum SpaceTime Coordinates of an Event
, 1997
"... The present paper deals with the quantum coordinates of an event in spacetime, individuated by a quantum object. It is known that these observables cannot be described by selfadjoint operators. We describe them by means of a normalized positive operator valued (POV) measure in the Minkowski spacetim ..."
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Cited by 4 (1 self)
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The present paper deals with the quantum coordinates of an event in spacetime, individuated by a quantum object. It is known that these observables cannot be described by selfadjoint operators. We describe them by means of a normalized positive operator valued (POV) measure in the Minkowski spacetime, satisfying a suitable covariance condition with respect to the Poincaré group. This POV measure determines the probability that a measurement of the coordinates of the event gives results belonging to a given set in spacetime. A general expression for the normalized covariant POV measures is given. PACS: 03.65.Bz quantum theory; 02.20.+b group theory. 1 1 Introduction. A quantum frame [1, 2, 3, 4] is a material quantum object that individuates, within the accuracy permitted by the indeterminacy relations, a frame of reference in the Minkowski spacetime. The observables which describe
A representation for compound quantum systems as individual entities: hard acts of creation and hidden correlations” Found. Phys
, 1998
"... We introduce an explicit definition for ’hidden correlations ’ on individual entities in a compound system: when one individual entity is measured, this induces a welldefined transition of the ’proper state ’ of the other individual entities. We prove that every compound quantum system described in ..."
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Cited by 4 (3 self)
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We introduce an explicit definition for ’hidden correlations ’ on individual entities in a compound system: when one individual entity is measured, this induces a welldefined transition of the ’proper state ’ of the other individual entities. We prove that every compound quantum system described in the tensor product of a finite number of Hilbert spaces can be uniquely represented as a collection of individual(ized) (peudo)entities between which there exist such hidden correlations. We investigate the significance of these hidden correlation representations within the socalled “creationdiscoveryapproach” and in particular their compatibility with the “hidden measurement formalism”. This leads us to the introduction of the notions of ’soft ’ and ’hard ’ ’acts of creation ’ and to the observation that our approach can be seen as a theory of (pseudo)individuals when compared to the standard quantum theory. (For a presentation of some of the ideas proposed in this paper within a quantum logical setting, yielding a structural theorem for the representation of a compound quantum system in terms of the Hilbert space tensor product, we refer to [18].) Key words: state, compound system, Hilbert space tensor product, act of creation, hidden measurement. 1 Introduction.
The Quantum Vacuum and the Cosmological Constant Problem
, 2000
"... The cosmological constant problem arises at the intersection between general relativity and quantum field theory, and is regarded as a fundamental problem in modern physics. In this paper we describe the historical and conceptual origin of the cosmological constant problem which is intimately conne ..."
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The cosmological constant problem arises at the intersection between general relativity and quantum field theory, and is regarded as a fundamental problem in modern physics. In this paper we describe the historical and conceptual origin of the cosmological constant problem which is intimately connected to the vacuum concept in quantum field theory. We critically discuss how the problem rests on the notion of physical real vacuum energy, and which relations between general relativity and quantum field theory are assumed in order to make the problem welldefined.