62 research outputs found
Quantum decoherence and an adiabatic process in macroscopic and mesoscopic systems
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
Distance dependent statistics in a P,T-invariant model
It is shown that in the P,T-invariant model with the mixed Chern-Simons term
the interaction of charge carriers leads to effective changing of their
statistics, which depends on distance between them. In particular, in the limit
of large distances fermions effectively turn into bosons.Comment: 8 pages, LATEX, Kiev Institute for Theoretical Physics preprint
ITP-93-16
Indeterministic Quantum Gravity; 5, Dynamics and Arrow of Time
This paper is a continuation of the papers [gr-qc/9409010, gr-qc/9505034, gr-qc/9603022, gr-qc/9609035] and is devoted to the riddle of the origin of the arrow of time. The problem of time orientation reduces to that of the difference between the past and the future. The riddle escapes solution in deterministic dynamics and in the dynamics of standard indeterministic quantum theory as well. In the dynamics of indeterministic quantum gravity, the past is reconstructible uniquely, whereas the future may be forecasted only on a probabilistic level. Thus the problems of the past and the future and, by the same token, of time orientation are solved
Indeterministic quantum gravity; 3, gravidynamics versus geometrodynamics: revision of the Einstein equation
This paper is a continuation of the papers [gr-qc/9409010, gr-qc/9505034]. A revision of the Einstein equation shows that its dynamic incompleteness, contrary to a popular opinion, cannot be circumvented by so-called coordinate conditions. Gravidynamics, i.e., dynamics for gravitational potentials g_{\mu\nu} is advanced, which differs from geometrodynamics of general relativity in that the former is based on a projected Einstein equation. Cosmic gravidynamics, due to a global structure of spacetime, is complete. The most important result is a possibility of the closed universe with a density below the critical one. Keywords: general relativity, cosmic time, cosmic space, Einstein equation, quantum, metric, indeterministi
Particles with distance dependent statistics at low temperatures
We consider a simplified model of particles with effectively distance
dependent statistics, that is particles coupled to a gauge field the Lagrangian
of which contains the Chern-Simons term. We analyze the low-lying states of the
two-particle system and show that under certain conditions they can exhibit
negative compressibility, hinting on a possible \`a la van der Vaals picture.Comment: 5 pages, LATEX, Bielefeld University preprint BI-TP 93/59, November
199
Cosmological Quantum Jump Dynamics; 1, The Principle of Cosmic Energy Determinacy, Equations of Motion, and Jumps Probabilities
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
Indeterministic Quantum Gravity and Cosmology; 9, Nonreality of Many-Place Gravitational Autolocalization: Why a Ball Is Not Located in Different Places at Once
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
Indeterministic Quantum Gravity and Cosmology; 2, Quantum Measurement
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, gr-qc/9802016, gr-qc/9802022]. We define a quantum measurement as a sequence of binary quantum jumps caused by a macroscopic apparatus. A dynamical theory of measurement is developed, the role of gravity and cosmology being emphasized
Indeterministic Quantum Gravity and Cosmology; 6, Predynamical Geometry of Spacetime Manifold, Supplementary Conditions for Metric, and CPT
This paper is a continuation of the papers [gr-qc/9409010, gr-qc/9505034, gr-qc/9603022, gr-qc/9609035, gr-qc/9609046]. The introduction of a prior, i.e., predynamical global geometry of spacetime manifold is substantiated, and the geometry is specified. The manifold is an infinite four-cylinder, or tube in the five-dimensional Euclidean space, the orthogonal section of the cylinder being the unit three-sphere. Supplementary conditions for metric are introduced geometrically, coordinate-independently, as opposed to coordinate conditions. Parity and time-reversal transformations are extended to the manifold specified. PT is equivalent to a rotation through \pi about an axis orthogonal to the cylinder axis. CPT invariance is discussed. Keywords: cosmic time, cosmic space, cylindrical manifol
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"
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
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