233 research outputs found

    Quantum decoherence and an adiabatic process in macroscopic and mesoscopic systems

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    Quantum decoherence is of primary importance for relaxation to an equilibrium distribution and, accordingly, for equilibrium processes. We demonstrate how coherence breaking implies evolution to a microcanonical distribution (``microcanonical postulate'') and, on that ground, consider an adiabatic process, in which there is no thermostat. We stress its difference from a zero-polytropic process, i.e., a process with zero heat capacity but involving a thermostat. We find the distribution for the adiabatic process and show that (i) in the classical limit this distribution is canonical, (ii) for macroscopic systems, the mean values of energy for adiabatic and zero-polytropic processes are the same, but its fluctuations are different, and (iii) in general, adiabatic and zero-polytropic processes are different, which is particularly essential for mesoscopic systems; for those latter, an adiabatic process is in general irreversible.Comment: 4 pages, LATEX, Elsevier style espcrc1.sty, to appear in Proceedings of ISQM-Tokyo '9

    Chern-Simons Field Theory and Generalizations of Anyons

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    It is well known that charges coupled to a pure Chern-Simons gauge field in (2+1) dimensions undergo an effective change of statistics, i.e., become anyons. We will consider several generalizations thereof, arising when the gauge field is more general. The first one is ``multispecies anyons''---charged particles of several species coupled to one, or possibly several, Chern-Simons fields. The second one is finite-size anyons, which are charged particles coupled to a gauge field described by the Chern-Simons term plus some other term. In fact, rigorously speaking, quasielectrons and quasiholes in the fractional quantum Hall effect are multispecies finite-size anyons. The third one is an analog of finite-size anyons which arises in a model with a mixed Chern-Simons term; notably, this model is P,T-invariant, which opens the way for practical applications even when there is no parity-breaking magnetic field.Comment: 6 pages, LATEX. Contributed paper at the International Europhysics Conference on High Energy Physics HEP-97 (Jerusalem, Israel, 19--26 August 1997

    Cosmological Quantum Jump Dynamics I. The Principle of Cosmic Energy Determinacy, Equations of Motion, and Jumps Probabilities

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    The universe, as a closed system, is for all time in a state with a determinate value of energy, i.e., in an eigenstate of the Hamiltonian. That is the principle of cosmic energy determinacy. The Hamiltonian depends on cosmic time through metric. Therefore there are confluence and branch points of energy levels. At branch points, quantum jumps must happen to prevent the violation of energy determinacy. Thus quantum jumps are a reaction against the propensity of the universe dynamics to that violation. On the basis of this idea, an internally consistent quantum jump dynamics is developed.Comment: 11 pages, LATEX 2

    Notes on Quantum Field Theory in Curved Spacetime: Problems Relating to the Concept of Particles and Hamiltonian Formalism

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    The aim of these notes is to elucidate some aspects of quantum field theory in curved spacetime, especially those relating to the notion of particles. A selection of issues relevant to wave-particle duality is given. The case of a generic curved spacetime is outlined. A Hamiltonian formulation of quantum field theory in curved spacetime is elaborated for a preferred reference frame with a separated space metric (a static spacetime and a reductive synchronous reference frame). Applications: (1) Black hole. (2) The universe; the cosmological redshift is obtained in the context of quantum field theory.Comment: 27 pages, LaTeX 2e. Substantially extended, sections on applications to black hole and universe adde

    Pulsating Massive Star: Phase Transitions in Superdense Matter

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    In the case of the energy-momentum tensor related to "ordinary" matter (perfect fluid representing spin 1/2 and 1 fields), the equations of general relativity result in cosmological and gravitational collapse singularities--due to the fulfilment of both the strong and weak energy conditions. According to great unified theories, in superdense matter (both hot and cold), phase transitions take place, symmetry between the strong and electroweak interactions is restored/broken, and a scalar field is created/annihilated. In the scalar field regime, the strong energy condition is broken, but the weak one holds. However, the continuity condition for the pressure on the surface of a contracting star results in the occurrence of a compensating pseudomatter field, for which both energy conditions are broken. On this basis, for a massive star predisposed to a gravitational collapse, a pulsation dynamics with no singularity is constructed.Comment: 15 pages, LaTeX 2

    General Relativity and Quantum Jumps: The Existence of Nondiffeomorphic Solutions to the Cauchy Problem in Nonempty Spacetime and Quantum Jumps as a Provider of a Canonical Spacetime Structure

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    It is shown that in spite of a generally accepted concept, there exist nondiffeomorphic solutions to the Cauchy problem in nonempty spacetime, which implies the necessity for canonical complementary conditions. It is nonlocal quantum jumps that provide a canonical global structure of spacetime manifold and, by the same token, the canonical complementary conditions.Comment: 13 pages, LATEX 2

    Comment on ``Additional analytically exact solutions for three-anyons'' and ``Fermion Ground State of Three Particles in a Harmonic Potential Well and Its Anyon Interpolation''

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    The claim put forward in [hep-th/9512051, hep-th/9612244] that the energies of the ``missing'' states of three anyons in a harmonic potential depend linearly on the statistics parameter, is incorrect because the wave functions proposed do not satisfy the anyonic interchange conditions.Comment: 2 pages, LATEX 2.0

    Quantum Fields in Curved Spacetime: Quantum-Gravitational Nonlocality and Conservation of Particle Numbers

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    We argue that the conventional quantum field theory in curved spacetime has a grave drawback: The canonical commutation relations for quantum fields and conjugate momenta do not hold. Thus the conventional theory should be denounced and the related results revised. A Hamiltonian version of the canonical formalism for a free scalar quantum field is advanced, and the fundamentals of an appropriate theory are constructed. The principal characteristic feature of the theory is quantum-gravitational nonlocality: The Schroedinger field operator at time t depends on the metric at t in the whole 3-space. Applications to cosmology and black holes are given, the results being in complete agreement with those of general relativity for particles in curved spacetime. A model of the universe is advanced, which is an extension of the Friedmann universe; it lifts the problem of missing dark matter. A fundamental and shocking result is the following: There is no particle creation in the case of a free quantum field in curved spacetime; in particular, neither the expanding universe nor black holes create particles.Comment: 17 pages, no figures, LATEX 2.0

    On Cosmological Spacetime Structure and Symmetry: Manifold as a Lie Group, Spinor Structure and Symmetry Group, Minkowski Metric, and Unnecessariness of Double-Valued Representations

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    It is shown that cosmological spacetime manifold has the structure of a Lie group and a spinor space. This leads naturally to the Minkowski metric on tangent spaces and the Lorentzian metric on the manifold and makes it possible to dispense with double-valued representations.Comment: 12 pages, LaTeX 2

    Indeterministic Quantum Gravity and Cosmology IX. Nonreality of Many-Place Gravitational Autolocalization: Why a Ball Is Not Located in Different Places at Once

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    This paper is a sequel to the series of papers [gr-qc/9409010, gr-qc/9505034, gr-qc/9603022, gr-qc/9609035, gr-qc/9609046, gr-qc/9704033, gr-qc/9704038, gr-qc/9708014], being an immediate continuation and supplement to the last of them, where gravitational autolocalization of a body has been considered. A resulting solution, which describes a one-place location, has been called gravilon. Here it is shown that a gravilon is the only solution, i.e., that many-place gravitational autolocalization is unreal. This is closely related to nonreality of tunneling in the conditions under consideration.Comment: 5 pages, LATEX 2.0
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