Bohmian mechanics and the Ghirardi–Rimini–Weber theory provide opposite resolutions of the quantum measurement problem: the former postulates additional variables (the particle positions) besides the wave function, whereas the latter implements spontaneous collapses of the wave function by a nonlinear and stochastic modification of Schrödinger's equation. Still, both theories, when understood appropriately, share the following structure: They are ultimately not about wave functions but about matter moving in space, represented by either particle trajectories, fields on space-time, or a discrete set of (...) space-time points. The role of the wave function then is to govern the motion of the matter. Introduction Bohmian Mechanics Ghirardi, Rimini, and Weber 3.1 GRWm 3.2 GRWf 3.3 Empirical equivalence between GRWm and GRWf Primitive Ontology 4.1 Primitive ontology and physical equivalence 4.2 Primitive ontology and symmetry 4.3 Without primitive ontology 4.4 Primitive ontology and quantum state Differences between BM and GRW 5.1 Primitive ontology and quadratic functionals 5.2 Primitive ontology and equivariance A Plethora of Theories 6.1 Particles, fields, and flashes 6.2 Schrödinger wave functions and many-worlds The Flexible Wave Function 7.1 GRWf without collapse 7.2 Bohmian mechanics with collapse 7.3 Empirical equivalence and equivariance What is a Quantum Theory without Observers? CiteULike Connotea Del.icio.us What's this? (shrink)
Bohmian mechanics and the Ghirardi–Rimini–Weber theory provide opposite resolutions of the quantum measurement problem: the former postulates additional variables (the particle positions) besides the wave function, whereas the latter implements spontaneous collapses of the wave function by a nonlinear and stochastic modification of Schrödinger's equation. Still, both theories, when understood appropriately, share the following structure: They are ultimately not about wave functions but about ‘matter’ moving in space, represented by either particle trajectories, fields on space-time, or a discrete set of (...) space-time points. The role of the wave function then is to govern the motion of the matter. IntroductionBohmian MechanicsGhirardi, Rimini, and WeberGRWmGRWfEmpirical equivalence between GRWm and GRWfPrimitive OntologyPrimitive ontology and physical equivalencePrimitive ontology and symmetryWithout primitive ontologyPrimitive ontology and quantum stateDifferences between BM and GRWPrimitive ontology and quadratic functionalsPrimitive ontology and equivarianceA Plethora of TheoriesParticles, fields, and flashesSchrödinger wave functions and many-worldsThe Flexible Wave FunctionGRWf without collapseBohmian mechanics with collapseEmpirical equivalence and equivarianceWhat is a Quantum Theory without Observers? (shrink)
The propositions, that what we see around us is real and that reality should be represented by the statevector, conflict with quantum theory. In quantum theory, the statevector can readily become a sum of states of comparable norm, each state representing a different reality. In this paper we present the Continuous Spontaneous Localization (CSL) theory, in which a modified Schrodinger equation, while scarcely affecting the dynamics of a microscopic system, rapidly "reduces" the statevector of a macroscopic system to a state (...) appropriate for representing individual reality. (shrink)
Recently it has been claimed that no extension of quantum theory can have improved predictive power, the statement following, according to the authors, from the assumptions of free will and of the correctness of quantum predictions concerning the correlations of measurement outcomes. Here we prove that the argument is basically flawed by an inappropriate use of the assumption of free will. In particular, among other implications, the claim, if correct, would imply that Bohmian Mechanics is incompatible with free will. This (...) statement, appearing in the paper, derives from the unjustified identification of free will with the no-signaling constraint and of a purely formal and not physical use of such a constraint. (shrink)
In this multiple-case study, I analyze the perceived importance of seven categories of institutional entrepreneurs (DiMaggio, Institutional patterns and organizations, Ballinger, Cambridge, MA, 1988 ) for the corporate social responsibility discourse of three multinational companies. With this study, I aim to significantly advance the empirical analysis of the CSR discourse for a better understanding of facts and fiction in the process of institutionalization of CSR in MNCs. I conducted 42 semi-structured face-to-face and phone interviews in two rounds with 30 (...) corporate managers from three multinational companies. The data has been analyzed using qualitative (multiple coding) and quantitative (ANOVA, χ 2 analysis) techniques. The findings indicate that one company is driven by civil society’s influence on consumer’s perception, the second company by direct attacks by civil society, agenda setting organizations and legislators, and the third by the pressure of large customers and legislators. The results suggest that the coping behaviors of MNCs at both extremes of the spectrum of perceived responsible behavior aim at (1) improving the business case for CSR and (2) increasing legitimacy in society, resulting in converging CSR perceptions, and fostering an institutionalization of CSR. (shrink)
After a brief account of theway quantum theory deals with naturalprocesses, the crucial problem that such atheory meets, the measurement or, better, themacro-objectification problem is discussed.The embarrassing aspects of the occurrence ofentangled states involving macroscopic systemsare analyzed in details. The famous example ofSchroedinger's cat is presented and it ispointed out how the combined interplay of thesuperposition principle and the ensuingentanglement raises some serious difficultiesin working out a satisfactory quantum worldview, agreeing with our definiteperceptions. The orthodox solution to themacro-objectification problem, i.e. (...) thepostulate of wave packet reduction, isanalyzed and is proved to be inconsistent withthe assumption that the theory governes alsothe measurement process. After these premises,the rest of the paper is devoted to discuss arecent proposal of overcoming the difficultiesof the standard formalism by acceptingnonlinear and stochastic modifications of thequantum dynamics. The proposed theory is shownto agree with all known predictions of thestandard theory concerning microscopic systemsand to account, on the basis of a universaldynamics which is assumed to govern allnatural processes, for wave packet reductionin measurement processes and, more important,to eliminate all the difficulties concerningmacroscopic situations. Actually, the proposedtheory allows one to take consistently amacrorealistic position about natural processes and about our definite perceptions. (shrink)
Quantum mechanics, with its revolutionary implications, has posed innumerable problems to philosophers of science. In particular, it has suggested reconsidering basic concepts such as the existence of a world that is, at least to some extent, independent of the observer, the possibility of getting reliable and objective knowledge about it, and the possibility of taking (under appropriate circumstances) certain properties to be objectively possessed by physical systems. It has also raised many others questions which are well known to those involved (...) in the debate on the interpretation of this pillar of modern science. One can argue that most of the problems are not only due to the intrinsic revolutionary nature of the phenomena which have led to the development of the theory. They are also related to the fact that, in its standard formulation and interpretation, quantum mechanics is a theory which is excellent (in fact it has met with a success unprecedented in the history of science) in telling us everything about what we observe, but it meets with serious difficulties in telling us what is. We are making here specific reference to the central problem of the theory, usually referred to as the measurement problem, or, with a more appropriate term, as the macro-objectification problem. It is just one of the many attempts to overcome the difficulties posed by this problem that has led to the development of Collapse Theories, i.e., to the Dynamical Reduction Program (DRP). As we shall see, this approach consists in accepting that the dynamical equation of the standard theory should be modified by the addition of stochastic and nonlinear terms. The nice fact is that the resulting theory is capable, on the basis of a unique dynamics which is assumed to govern all natural processes, to account at the same time for all well-established.. (shrink)
In this paper we study the logic of relational and partial variable sets, seen as a generalization of set-valued presheaves, allowing transition functions to be arbitrary relations or arbitrary partial functions. We find that such a logic is the usual intuitionistic and co-intuitionistic first order logic without Beck and Frobenius conditions relative to quantifiers along arbitrary terms. The important case of partial variable sets is axiomatizable by means of the substitutivity schema for equality. Furthermore, completeness, incompleteness and independence results are (...) obtained for different kinds of Beck and Frobenius conditions. (shrink)
The paper examines some of the questions emerging from the debate on mindreading regarding Quine's legacy and contribution to a new agenda on the issue. Since mindreading is an exercise in folk-psychology, a) which role folk psychology has to play according to Quine? b) was Quine's account of mindreading closer to theory-theory, simulation theory or hybrid theory? c) was Quine a rationality theorist? d) are hybrid-theory and rationality theory incompatible as many would suggest? On the score of the answers to (...) these questions, the paper tries to suggest a Quinean inspired blend of rationality-based and hybrid view-based strategies to explain mindreading. (shrink)
AnthonyDiMaggio: The "humanitarian reconstruction" of Iraq has been acknowledged to a large degree as a failure in the corporate press. It's interesting, though, to see the reasons given for why: the resistance is hampering reconstruction, there wasn't perfect foresight by the Bush administration in the reconstruction coordination planning process, the excessive "rapid personnel shifts" of those Americans involved in rebuilding, American money has "necessarily" gone to "pacification" instead of rebuilding, etc. What seems to be systematically omitted here (...) is any real responsibility placed on the Bush Administration for its failure to make humanitarian reconstruction a high priority. (shrink)
We reconsider the problem of the compatibility of quantum nonlocality and the requests for a relativistically invariant theoretical scheme. We begin by discussing a recent important paper by T. Norsen on this problem and we enlarge our considerations to give a general picture of the conceptually relevant issue to which this paper is devoted.
The New Economic Windows Series, derived from Massimo Salzano's ideas and work, incorporates material from textbooks, monographs and conference proceedings that deals with both the theoretical and applied aspects of various sub-disciplines ...
The problem of getting a relativistic generalization of the CSL dynamical reduction model, which has been presented in part I, is discussed. In so doing we have the opportunity to introduce the idea of a stochastically invariant theory. The theoretical model we present, that satisfies this kind of invariance requirement, offers us the possibility to reconsider, from a new point of view, some conceptually relevant issues such as nonlocality, the legitimacy of attributing elements of physical reality to physical systems and (...) the problem of establishing causal relations between physical events. (shrink)
Consideration is given to recent attempts to solve the objectification problem of quantum mechanics by considering nonlinear and stochastic modifications of Schrödinger's evolution equation. Such theories agree with all predictions of standard quantum mechanics concerning microsystems but forbid the occurrence of superpositions of macroscopically different states. It is shown that the appropriate interpretation for such theories is obtained by replacing the probability densities of standard quantum mechanics with mass densities in real space. Criteria allowing a precise characterization of the idea (...) of similarity and difference of macroscopic situations are presented and it is shown how they lead to a theoretical picture which is fully compatible with a macrorealistic position about natural phenomena. (shrink)
In view of the arguments put forward by Clifton and Monton [this volume], we reconsider the alleged conflict of dynamical reduction models with the enumeration principle. We prove that our original analysis of such a problem is correct, that the GRW model does not meet any difficulty and that the reasoning of the above authors is inappropriate since it does not take into account the correct interpretation of the dynamical reduction theories.
In a recent paper, Conway and Kochen proposed what is now known as the “Free Will theorem” which, among other things, should prove the impossibility of combining GRW models with special relativity, i.e., of formulating relativistically invariant models of spontaneous wavefunction collapse. Since their argument basically amounts to a non-locality proof for any theory aiming at reproducing quantum correlations, and since it was clear since very a long time that any relativistic collapse model must be non-local in some way, we (...) discuss why the theorem of Conway and Kochen does not affect the program of formulating relativistic GRW models. (shrink)
In this paper we reconsider the constraints which are imposed by relativistic requirements to any model of dynamical reduction. We review the debate on the subject and we call attention on the fundamental contributions by Aharonov and Albert. Having done this we present a new formulation, which is much simpler and more apt for our analysis, of the proposal put forward by these authors to perform measurements of nonlocal observables by means of local interactions and detections. We take into account (...) recently proposed relativistic models of dynamical reduction and we show that, in spite of some mathematical difficulties related to the appearence of divergences, they represent a perfectly appropriate conceptual framework which meets all necessary requirements for a relativistic account of wave packet reduction. Subtle questions like the appropriate way to deal with counterfactual reasoning in a relativistic and nonlocal context are also analyzed in detail. (shrink)
n my adopted home of Puritan New England, I have learned that personal indulgence is a vice to be tolerated only at rare intervals. Combine this stricture with two further principles and this essay achieves its rationale: first, that we celebrate in hundreds and their easy multiples (the Columbian quincentenary and the fiftieth anniversary of DiMaggio's hitting streak—both about equally important, and only the latter an unambiguous good); second, that geologists learn to take the long view.