811 research outputs found

    Scientific Realism without the Wave-Function: An Example of Naturalized Quantum Metaphysics

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    Scientific realism is the view that our best scientific theories can be regarded as (approximately) true. This is connected with the view that science, physics in particular, and metaphysics could (and should) inform one another: on the one hand, science tells us what the world is like, and on the other hand, metaphysical principles allow us to select between the various possible theories which are underdetermined by the data. Nonetheless, quantum mechanics has always been regarded as, at best, puzzling, if not contradictory. As such, it has been considered for a long time at odds with scientific realism, and thus a naturalized quantum metaphysics was deemed impossible. Luckily, now we have many quantum theories compatible with a realist interpretation. However, scientific realists assumed that the wave-function, regarded as the principal ingredient of quantum theories, had to represent a physical entity, and because of this they struggled with quantum superpositions. In this paper I discuss a particular approach which makes quantum mechanics compatible with scientific realism without doing that. In this approach, the wave-function does not represent matter which is instead represented by some spatio-temporal entity dubbed the primitive ontology: point-particles, continuous matter fields, space-time events. I argue how within this framework one develops a distinctive theory-construction schema, which allows to perform a more informed theory evaluation by analyzing the various ingredients of the approach and their inter-relations

    From No-signaling to Spontaneous Localization Theories

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    GianCarlo Ghirardi passed away on June 1st, 201. He would have turned 83 on October 28, 2018. He was without any doubt one of the most prominent theoretical physicists working on the foundation and the philosophy of quantum mechanics. In this paper I review some of his achievements and underline how his research influenced the philosophy of physics community

    A New Argument for the Nomological Interpretation of the Wave Function: The Galilean Group and the Classical Limit of Nonrelativistic Quantum Mechanics

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    In this paper I investigate, within the framework of realistic interpretations of the wave function in nonrelativistic quantum mechanics, the mathematical and physical nature of the wave function. I argue against the view that mathematically the wave function is a two-component scalar field on configuration space. First, I review how this view makes quantum mechanics non- Galilei invariant and yields the wrong classical limit. Moreover, I argue that interpreting the wave function as a ray, in agreement many physicists, Galilei invariance is preserved. In addition, I discuss how the wave function behaves more similarly to a gauge potential than to a field. Finally I show how this favors a nomological rather than an ontological view of the wave function

    THE ACCOUNTING OF THE ECONOMIC ENTITIES, BETWEEN RIGOURS AND OPTIONS

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    This paper is addressing to the issues of the existence of some options in choosing accounting policies and techniques. We proposed ourselves to establish to what extent the choices made in meeting the financial accounting function of the enterprise are free and how the options of those who prepare the annual accounts of economic entities are limited. To achieve this goal we considered necessary to study the regulations, the rules applicable to the area of the accounting of the economic entities. The work will respond to two questions: 1. What is the content of the set of financial statements and who must report (where they make)? and 2. Assess how the structures of assets, liabilities, equity, expenses, income, etc. the financial statements? The ultimate objective of this work is to provide specialist financial and accounting opinion documented to support the decisions that it should adopt in the exercise of his powers.choice, financial statements, recognition, rules, valuation

    Defective Coloring on Classes of Perfect Graphs

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    In Defective Coloring we are given a graph GG and two integers χd\chi_d, Δ∗\Delta^* and are asked if we can χd\chi_d-color GG so that the maximum degree induced by any color class is at most Δ∗\Delta^*. We show that this natural generalization of Coloring is much harder on several basic graph classes. In particular, we show that it is NP-hard on split graphs, even when one of the two parameters χd\chi_d, Δ∗\Delta^* is set to the smallest possible fixed value that does not trivialize the problem (χd=2\chi_d = 2 or Δ∗=1\Delta^* = 1). Together with a simple treewidth-based DP algorithm this completely determines the complexity of the problem also on chordal graphs. We then consider the case of cographs and show that, somewhat surprisingly, Defective Coloring turns out to be one of the few natural problems which are NP-hard on this class. We complement this negative result by showing that Defective Coloring is in P for cographs if either χd\chi_d or Δ∗\Delta^* is fixed; that it is in P for trivially perfect graphs; and that it admits a sub-exponential time algorithm for cographs when both χd\chi_d and Δ∗\Delta^* are unbounded

    Primitive Ontology and the Structure of Fundamental Physical Theories

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    On the Collective Mode Spectrum for Composite Fermions at 1/3 Filling Factor

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    The collective mode spectrum of the composite fermion state 1/3 filling factor is evaluated. At zero momentum, the result coincides with the cyclotron energy at the external magnetic field value, and not at the effective magnetic field, in spite of the fact that only the former enters in the equations, thus, the Kohn theorem is satisfied. Unexpectedly, in place of a magneto roton minimum, the collective mode gets a treshold indicating the instability of the mean field composite fermion state under the formation of crystalline structures. However, the question about if if this outcome only appears within the mean field approximation should be further considered.Comment: 17 pages, one figure. Submitted to Int. Jour. Mod. Phys.
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