3,040 research outputs found
A Stepwise Planned Approach to the Solution of Hilbert's Sixth Problem. III : Measurements and von Neumann Projection/Collapse Rule
Supmech, the universal mechanics developed in the previous two papers,
accommodates both quantum and classical mechanics as subdisciplines (a brief
outline is included for completeness); this feature facilitates, in a supmech
based treatment of quantum measurements, an unambiguous treatment of the
apparatus as a quantum system approximated well by a classical one. Taking
explicitly into consideration the fact that observations on the apparatus are
made when it has `settled down after the measurement interaction' and are
restricted to macroscopically distinguishable pointer readings, the unwanted
superpositions of (system + apparatus) states are shown to be suppressed; this
provides a genuinely physics based justification for the (traditionally
\emph{postulated}) von Neumann projection/collapse rule. The decoherence
mechanism brought into play by the stated observational constraints is free
from the objections against the traditional decoherence program.Comment: 29 pages; one section and two references added; results unchange
Effect of stripe order strength for the Nernst effect in La_{2-x}Sr_xCu_4 single crystals
We have precisely measured the Nernst effect in Nd-doped
LaSrCuO single crystals with controlling the strength
(stability) of the stripe order. We found that the onset temperature
, where the Nernst signal starts increasing, does not change
conspicuously in spite of Nd-doping. At low temperatures, on the other hand,
the absolute value of the Nernst signal is strongly suppressed in accordance
with the strength of the stripe order. These results imply that the fluctuation
of (charge) stripe order enhances the Nernst signal below at high
temperatures, and then the stripe order enhanced by Nd-doping suppresses the
superconducting fluctuation to reduce the Nernst signal at low temperatures. We
also observed an increase of the Nernst signal below the charge order
temperature which is observed in diffraction measurement.Comment: 3pages, 2figure
Anisotropic turbulence in weakly stratified rotating magnetoconvection
Numerical simulations of the 3D MHD-equations that describe rotating
magnetoconvection in a Cartesian box have been performed using the code
NIRVANA. The characteristics of averaged quantities like the turbulence
intensity and the turbulent heat flux that are caused by the combined action of
the small-scale fluctuations are computed. The correlation length of the
turbulence significantly depends on the strength and orientation of the
magnetic field and the anisotropic behavior of the turbulence intensity induced
by Coriolis and Lorentz force is considerably more pronounced for faster
rotation. The development of isotropic behavior on the small scales -- as it is
observed in pure rotating convection -- vanishes even for a weak magnetic field
which results in a turbulent flow that is dominated by the vertical component.
In the presence of a horizontal magnetic field the vertical turbulent heat flux
slightly increases with increasing field strength, so that cooling of the
rotating system is facilitated. Horizontal transport of heat is always directed
westwards and towards the poles. The latter might be a source of a large-scale
meridional flow whereas the first would be important in global simulations in
case of non-axisymmetric boundary conditions for the heat flux.Comment: 13 pages 11 figure
Pseudoconvex domains spread over complex homogeneous manifolds
Using the concept of inner integral curves defined by Hirschowitz we
generalize a recent result by Kim, Levenberg and Yamaguchi concerning the
obstruction of a pseudoconvex domain spread over a complex homogeneous manifold
to be Stein. This is then applied to study the holomorphic reduction of
pseudoconvex complex homogeneous manifolds X=G/H. Under the assumption that G
is solvable or reductive we prove that X is the total space of a G-equivariant
holomorphic fiber bundle over a Stein manifold such that all holomorphic
functions on the fiber are constant.Comment: 21 page
Quantum Bayesian implementation
Bayesian implementation concerns decision making problems when agents have
incomplete information. This paper proposes that the traditional sufficient
conditions for Bayesian implementation shall be amended by virtue of a quantum
Bayesian mechanism. In addition, by using an algorithmic Bayesian mechanism,
this amendment holds in the macro world.Comment: 14 pages, 3 figure
On hyperbolicity of SU(2)-equivariant, punctured disc bundles over the complex affine quadric
Given a holomorphic line bundle over the complex affine quadric , we
investigate its Stein, SU(2)-equivariant disc bundles. Up to equivariant
biholomorphism, these are all contained in a maximal one, say .
By removing the zero section to one obtains the unique Stein,
SU(2)-equivariant, punctured disc bundle over which contains entire
curves. All other such punctured disc bundles are shown to be Kobayashi
hyperbolic.Comment: 15 pages, v2: minor changes, to appear in Transformation Group
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