13,801 research outputs found
The H.E.S.S. View of the Central 200 Parsecs
The inner few hundred parsecs of our galaxy provide a laboratory for the
study of the production and propagation of energetic particles.
Very-high-energy gamma-rays provide an effective probe of these processes and,
especially when combined with data from other wave-bands, gamma-rays
observations are a powerful diagnostic tool. Within this central region, data
from the H.E.S.S. instrument have revealed three discrete sources of
very-high-energy gamma-rays and diffuse emission correlated with the
distribution of molecular material. Here I provide an overview of these recent
results from H.E.S.S.Comment: Proceedings of the Galactic Centre Workshop 200
Possible Experience: from Boole to Bell
Mainstream interpretations of quantum theory maintain that violations of the
Bell inequalities deny at least either realism or Einstein locality. Here we
investigate the premises of the Bell-type inequalities by returning to earlier
inequalities presented by Boole and the findings of Vorob'ev as related to
these inequalities. These findings together with a space-time generalization of
Boole's elements of logic lead us to a completely transparent Einstein local
counterexample from everyday life that violates certain variations of the Bell
inequalities. We show that the counterexample suggests an interpretation of the
Born rule as a pre-measure of probability that can be transformed into a
Kolmogorov probability measure by certain Einstein local space-time
characterizations of the involved random variables.Comment: Published in: EPL, 87 (2009) 6000
Semiconductor superlattice photodetectors
A superlattice photomultiplier and a photodetector based on the real space transfer mechanism were studied. The wavelength for the first device is of the order of a micron or flexible corresponding to the bandgap absorption in a semiconductor. The wavelength for the second device is in the micron range (about 2 to 12 microns) corresponding to the energy of the conduction band edge discontinuity between an Al/(sub x)Ga(sub 1-x)As and GaAs interface. Both devices are described
Semiconductor superlattice photodetectors
Two novel types of superlattice photodetectors were studied. The first was a superlattice photomultiplier and the second a photodetector based on the real space transfer mechanism. A summary of the results is presented
Semiconductor superlattice photodetectors
Superlattice photodetectors were investigated. A few major physical processes in the quantum-well heterostructures related to the photon detection and electron conduction mechanisms, the field effect on the wave functions and the energy levels of the electrons, and the optical absorption with and without the photon assistance were studied
The liquid-glass transition of silica
We studied the liquid-glass transition of by means of replica theory,
utilizing an effective pair potential which was proved to reproduce a few
experimental features of silica. We found a finite critical temperature ,
where the system undergoes a phase transition related to replica symmetry
breaking, in a region where experiments do not show any transition. The
possible sources of this discrepancy are discussed.Comment: 14 pages, 6 postscript figures. Revised version accepted for
pubblication on J.Chem.Phy
Inter-Intra Molecular Dynamics as an Iterated Function System
The dynamics of units (molecules) with slowly relaxing internal states is
studied as an iterated function system (IFS) for the situation common in e.g.
biological systems where these units are subjected to frequent collisional
interactions. It is found that an increase in the collision frequency leads to
successive discrete states that can be analyzed as partial steps to form a
Cantor set. By considering the interactions among the units, a self-consistent
IFS is derived, which leads to the formation and stabilization of multiple such
discrete states. The relevance of the results to dynamical multiple states in
biomolecules in crowded conditions is discussed.Comment: 7 pages, 7 figures. submitted to Europhysics Letter
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