2,403 research outputs found
Quantum features in statistical observations of "timeless" classical systems
We pursue the view that quantum theory may be an emergent structure related
to large space-time scales. In particular, we consider classical Hamiltonian
systems in which the intrinsic proper time evolution parameter is related
through a probability distribution to the discrete physical time. This is
motivated by studies of ``timeless'' reparametrization invariant models, where
discrete physical time has recently been constructed based on coarse-graining
local observables. Describing such deterministic classical systems with the
help of path-integrals, primordial states can naturally be introduced which
follow unitary quantum mechanical evolution in suitable limits.Comment: 7 pages. Invited talk at Int. Workshop Trends and Perspectives on
Extensive and Non-Extensive Statistical Mechanics, Angra dos Reis (Brazil),
Nov. 2003. To appear in Physica
Vacuum-Induced Quantum Decoherence and the Entropy Puzzle
Or: ``How to generate an ensemble in a single event?'' Following recent work
on entropy in strong interactions, I explain the concept of environment-induced
quantum decoherence in elementary quantum mechanics. The classically chaotic
inverted oscillator becomes partially decoherent already in the environment of
a single other oscillator performing only vacuum fluctuations. One finds
exponential entropy growth in the subsystem with a Lyapunov exponent, which
approaches the classical one for weak coupling.
Presented at the Workshops on ``Quantum Infrared Physics'', Paris,
6 - 10.6.94, and ``QCD 94'', Montpellier, 7 - 13.7.94.
Invited talk at the NATO Adv. Res. Workshop on ``Hot Hadronic Matter'',
Divonne, 27.6. - 1.7.94. To appear in the Proceedings.Comment: 12 pages, CERN-TH.7372/9
Lithuanian Retail Internationalization: Features and Prospects
Purpose of the article: To distinguish and describe Lithuanian retail internationalization of the peculiarities in the last twenty-four years and bases on the changes in the future. Methodology/methods: The retail internationalization literature explores the theories, concepts, experiences in different countries is the methodological basis for the assessment of the process and the prospect of these process changes in Lithuania. Lithuanian retail internationalization progress of the investigation from the beginning, development and future prospects is divided into three phases. From a methodological point of view, this is a difficult research because even after twenty years. Scientific aim: To analyse retail internationalization process in Lithuania – features and prospects. Findings: Investigate and evaluate three Lithuanian retail internationalization stages showed that each of them has distinct features. A survey of retailers allowed to set retail internationalization level in 2013. Conclusions: The retail trade internationalisation process in Lithuania, which started immediately after the destruction of the socialist economy and proceeded as the foundation for market economy was being laid, was particular in the sense that famous foreign retail trade companies did not immediately enter the Lithuanian retail market. The characteristic feature of the process in Lithuania was the establishment of joint capital companies, while individual foreign businessmen often started their business in the country by opening their first store. Research limitations: no interest of retailers to be in contact regarding research and wide theme was as serious limitations to find out and explore the Lithuanian retail internationalization features. This is the original article, exploring the small market of retail internationalization process characteristics from its beginning until 2014
Four questions for quantum-classical hybrid theory
Four questions are discussed which may be addressed to any proposal of a
quantum-classical hybrid theory which concerns the direct coupling of classical
and quantum mechanical degrees of freedom. In particular, we consider the
formulation of hybrid dynamics presented recently in Ref.[1]. This linear
theory differs from the nonlinear ensemble theory of Hall and Reginatto, but
shares with it to fulfil all consistency requirements discussed in the
literature, while earlier attempts failed. - Here, we additionally ask: Does
the theory allow for superposition, separable, and entangled states originating
in the quantum mechanical sector? Does it allow for "Free Will", as introduced,
in this context, by Diosi [2]. Is it local? Does it provide hints for the
emergence of quantum mechanics from dynamics beneath?Comment: 16 pages - based on talk at the Conference on Emergent Quantum
Mechanics / Heinz von Foerster Congress (Vienna University, Nov. 11-13, 2011
Quantum Mechanics and Discrete Time from "Timeless" Classical Dynamics
We study classical Hamiltonian systems in which the intrinsic proper time
evolution parameter is related through a probability distribution to the
physical time, which is assumed to be discrete. - This is motivated by the
``timeless'' reparametrization invariant model of a relativistic particle with
two compactified extradimensions. In this example, discrete physical time is
constructed based on quasi-local observables. - Generally, employing the
path-integral formulation of classical mechanics developed by Gozzi et al., we
show that these deterministic classical systems can be naturally described as
unitary quantum mechanical models. The emergent quantum Hamiltonian is derived
from the underlying classical one. It is closely related to the Liouville
operator. We demonstrate in several examples the necessity of regularization,
in order to arrive at quantum models with bounded spectrum and stable
groundstate.Comment: 24 pages, 1 figure. Lecture given at DICE 2002. To be published in:
Decoherence and Entropy in Complex Systems, Lecture Notes in Physics
(Springer-Verlag, Berlin 2003). - Comprises quant-ph/0306096 and
gr-qc/0301109, additional reference
Determinism and a supersymmetric classical model of quantum fields
A quantum field theory is described which is a supersymmetric classical
model. -- Supersymmetry generators of the system are used to split its
Liouville operator into two contributions, with positive and negative spectrum,
respectively. The unstable negative part is eliminated by a positivity
constraint on physical states, which is invariant under the classical
Hamiltonian flow. In this way, the classical Liouville equation becomes a
functional Schroedinger equation of a genuine quantum field theory. Thus, 't
Hooft's proposal to reconstruct quantum theory as emergent from an underlying
deterministic system, is realized here for a field theory. Quantization is
intimately related to the constraint, which selects the part of Hilbert space
where the Hamilton operator is positive. This is seen as dynamical symmetry
breaking in a suitably extended model, depending on a mass scale which
discriminates classical dynamics beneath from emergent quantum mechanical
behaviour.Comment: 8 pages, RevTeX. Based on talk at DICE2004, Piombino (Italy),
September 1-4, 2004. -- To appear in Brazilian Journal of Physic
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