23,378 research outputs found
The neutrino self-energy in a magnetized medium
In this work we calculate the neutrino self-energy in presence of a
magnetized medium. The magnetized medium consists of electrons, positrons,
neutrinos and a uniform classical magnetic field. The calculation is done
assuming the background magnetic field is weak compared to the -Boson mass
squared, as a consequence of which only linear order corrections in the field
are included in the boson propagator. The electron propagator consists all
order corrections in the background field. Although the neutrino self-energy in
a magnetized medium in various limiting cases has been calculated previously in
this article we produce the most general expression of the self-energy in
absence of the Landau quantization of the charged gauge fields. We calculate
the effect of the Landau quantization of the charged leptons on the neutrino
self-energy in the general case. Our calculation is specifically suited for
situations where the background plasma may be CP symmetric.Comment: 13 Pages, Latex file. Minor corrections included. To be published in
Modern Physics Letters
Characterization of soft stripe-domain deformations in Sm-C and Sm-C* liquid-crystal elastomers
The neoclassical model of Sm-C (and Sm-C*) elastomers developed by Warner and Adams predicts a class of “soft” (zero energy) deformations. We find and describe the full set of stripe domains—laminate structures in which the laminates alternate between two different deformations—that can form between pairs of these soft deformations. All the stripe domains fall into two classes, one in which the smectic layers are not bent at the interfaces, but for which—in the Sm-C* case—the interfaces are charged, and one in which the smectic layers are bent but the interfaces are never charged. Striped deformations significantly enhance the softness of the macroscopic elastic response
Local asymptotic minimax risk bounds in a locally asymptotically mixture of normal experiments under asymmetric loss
Local asymptotic minimax risk bounds in a locally asymptotically mixture of
normal family of distributions have been investigated under asymmetric loss
functions and the asymptotic distribution of the optimal estimator that attains
the bound has been obtained.Comment: Published at http://dx.doi.org/10.1214/074921706000000527 in the IMS
Lecture Notes--Monograph Series
(http://www.imstat.org/publications/lecnotes.htm) by the Institute of
Mathematical Statistics (http://www.imstat.org
Energy Landscape and Overlap Distribution of Binary Lennard-Jones Glasses
We study the distribution of overlaps of glassy minima, taking proper care of
residual symmetries of the system. Ensembles of locally stable, low lying
glassy states are efficiently generated by rapid cooling from the liquid phase
which has been equilibrated at a temperature . Varying , we
observe a transition from a regime where a broad range of states are sampled to
a regime where the system is almost always trapped in a metastable glassy
state. We do not observe any structure in the distribution of overlaps of
glassy minima, but find only very weak correlations, comparable in size to
those of two liquid configurations.Comment: 7 pages, 5 figures, uses europhys-style. Minor notational changes,
typos correcte
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