1,914 research outputs found
Note on the Relativistic Thermodynamics of Moving Bodies
We employ a novel thermodynamical argument to show that, at the macroscopic
level,there is no intrinsic law of temperature transformation under Lorentz
boosts. This result extends the corresponding microstatistical one of earlier
works to the purely macroscopic regime and signifies that the concept of
temperature as an objective entity is restricted to the description of bodies
in their rest frames. The argument on which this result is based is centred on
the thermal transactions between a body that moves with uniform velocity
relative to a certain inertial frame and a thermometer, designed to measure its
temperature, that is held at rest in that frame.Comment: To be published in J. Phys. A. A few minor corrections have been made
to the earlier version of this articl
Thermal behavior induced by vacuum polarization on causal horizons in comparison with the standard heat bath formalism
Modular theory of operator algebras and the associated KMS property are used
to obtain a unified description for the thermal aspects of the standard heat
bath situation and those caused by quantum vacuum fluctuations from
localization. An algebraic variant of lightfront holography reveals that the
vacuum polarization on wedge horizons is compressed into the lightray
direction. Their absence in the transverse direction is the prerequisite to an
area (generalized Bekenstein-) behavior of entropy-like measures which reveal
the loss of purity of the vacuum due to restrictions to wedges and their
horizons. Besides the well-known fact that localization-induced (generalized
Hawking-) temperature is fixed by the geometric aspects, this area behavior
(versus the standard volume dependence) constitutes the main difference between
localization-caused and standard thermal behavior.Comment: 15 page Latex, dedicated to A. A. Belavin on the occasion of his 60th
birthda
How far does the analogy between causal horizon-induced thermalization with the standard heat bath situation go?
After a short presentation of KMS states and modular theory as the unifying
description of thermalizing systems we propose the absence of transverse vacuum
fluctuations in the holographic projections as the mechanism for an area
behavior (the transverse area) of localization entropy as opposed to the volume
dependence of ordinary heat bath entropy. Thermalization through causal
localization is not a property of QM, but results from the omnipresent vacuum
polarization in QFT and does not require a Gibbs type ensemble avaraging
(coupling to a heat bath).Comment: 10 pages, based on talk given at the 2002 Londrina Winter Schoo
Off-Diagonal Long-Range Order: Meissner Effect and Flux Quantization
There has been a proof by Sewell that the hypothesis of off-diagonal
long-range order in the reduced density matrix implies the Meissner
effect. We present in this note an elementary and straightforward proof that
not only the Meissner effect but also the property of magnetic flux
quantization follows from the hypothesis. It is explicitly shown that the two
phenomena are closely related, and phase coherence is the origin for both.Comment: 11 pages, Latex fil
Quantum macrostatistical picture of nonequilibrium steady states
We employ a quantum macrostatistical treatment of irreversible processes to
prove that, in nonequilibrium steady states, (a) the hydrodynamical observables
execute a generalised Onsager-Machlup process and (b) the spatial correlations
of these observables are generically of long range. The key assumptions behind
these results are a nonequilibrium version of Onsager's regression hypothesis,
together with certain hypotheses of chaoticity and local equilibrium for
hydrodynamical fluctuations.Comment: TeX, 13 page
Distillability and positivity of partial transposes in general quantum field systems
Criteria for distillability, and the property of having a positive partial
transpose, are introduced for states of general bipartite quantum systems. The
framework is sufficiently general to include systems with an infinite number of
degrees of freedom, including quantum fields. We show that a large number of
states in relativistic quantum field theory, including the vacuum state and
thermal equilibrium states, are distillable over subsystems separated by
arbitrary spacelike distances. These results apply to any quantum field model.
It will also be shown that these results can be generalized to quantum fields
in curved spacetime, leading to the conclusion that there is a large number of
quantum field states which are distillable over subsystems separated by an
event horizon.Comment: 25 pages, 2 figures. v2: Typos removed, references and comments
added. v3: Expanded introduction and reference list. To appear in Rev. Math.
Phy
Deriving Bisimulation Congruences: 2-categories vs precategories
G-relative pushouts (GRPOs) have recently been proposed by the authors as a new foundation for Leifer and Milner’s approach to deriving labelled bisimulation congruences from reduction systems. This paper develops the theory of GRPOs further, arguing that they provide a simple and powerful basis towards a comprehensive solution. As an example, we construct GRPOs in a category of ‘bunches and wirings.’ We then examine the approach based on Milner’s precategories and Leifer’s functorial reactive systems, and show that it can be recast in a much simpler way into the 2-categorical theory of GRPOs
Off-Diagonal Long-Range Order in Bose Liquids: Irrotational Flow and Quantization of Circulation
On the basis of gauge invariance, it is proven in an elementary and
straightforward manner, but without invoking any {\it ad hoc} assumption, that
the existence of off-diagonal long-range order in one-particle reduced density
matrix in Bose liquids implies both the irrotational flow in a simply connected
region and the quantization of circulation in a multiply connected region, the
two fundamental properties of a Bose superfluid. The origin for both is the
phase coherence of condensate wave-functions. Some relevant issues are also
addressed.Comment: Revtex, 4 pages, no figure
The Measurement Process in Local Quantum Theory and the EPR Paradox
We describe in a qualitative way a possible picture of the Measurement
Process in Quantum Mechanics, which takes into account: 1. the finite and non
zero time duration T of the interaction between the observed system and the
microscopic part of the measurement apparatus; 2. the finite space size R of
that apparatus; 3. the fact that the macroscopic part of the measurement
apparatus, having the role of amplifying the effect of that interaction to a
macroscopic scale, is composed by a very large but finite number N of
particles. The conventional picture of the measurement, as an instantaneous
action turning a pure state into a mixture, arises only in the limit in which N
and R tend to infinity, and T tends to 0. We sketch here a proposed scheme,
which still ought to be made mathematically precise in order to analyse its
implications and to test it in specific models, where we argue that in Quantum
Field Theory this picture should apply to the unique time evolution expressing
the dynamics of a given theory, and should comply with the Principle of
Locality. We comment on the Einstein Podolski Rosen thought experiment (partly
modifying the discussion on this point in an earlier version of this note),
reformulated here only in terms of local observables (rather than global ones,
as one particle or polarisation observables). The local picture of the
measurement process helps to make it clear that there is no conflict with the
Principle of Locality.Comment: 18 page
- …