10,759 research outputs found
Dynamics of Fluxon Lattice in Two Coupled Josephson Junctions
We study theoretically the dynamics of a fluxon Lattice (FL) in two coupled
Josephson junctions. We show that when the velocity of the moving FL exceeds
certain values , sharp resonances arise in the system which are
related to the excitation of the optical and acoustic collective modes. In the
interval a reconstruction of the FL occurs. We also establish that
one can excite localized nonlinear distortions (dislocations) which may
propagate through the FL and carry an arbitrary magnetic flux.Comment: 4 pages, 3 figures, corected typo
Energy Resolved Supercurrent between two superconductors
In this paper I study the energy resolved supercurrent of a junction
consisting of a dirty normal metal between two superconductors. I also consider
a cross geometry with two additional arms connecting the above mentioned
junction with two normal reservoirs at equal and opposite voltages. The
dependence of the supercurrent between the two superconductors on the applied
voltages is studied.Comment: revtex, 7 pages, 8 figures. accepted by Phys. Rev.
Pion Polarizability in the NJL model and Possibilities of its Experimental Studies in Coulomb Nuclear Scattering
The charge pion polarizability is calculated in the Nambu-Jona-Lasinio model,
where the quark loops (in the mean field approximation) and the meson loops (in
the approximation) are taken into account. We show that quark loop
contribution dominates, because the meson loops strongly conceal each other.
The sigma-pole contribution plays the main role and
contains strong t-dependence of the effective pion polarizability at the region
. Possibilities of experimental test of this sigma-pole
effect in the reaction of Coulomb Nuclear Scattering are estimated for the
COMPASS experiment.Comment: 11 pages, 8 figure
Non-abelian 4-d black holes, wrapped 5-branes, and their dual descriptions
We study extremal and non-extremal generalizations of the regular non-abelian
monopole solution of hep-th/9707176, interpreted in hep-th/0007018 as 5-branes
wrapped on a shrinking S^2. Naively, the low energy dynamics is pure N=1
supersymmetric Yang-Mills. However, our results suggest that the scale of
confinement and chiral symmetry breaking in the Yang-Mills theory actually
coincides with the Hagedorn temperature of the little string theory. We find
solutions with regular horizons and arbitrarily high Hawking temperature.
Chiral symmetry is restored at high energy density, corresponding to large
black holes. But the entropy of the black hole solutions decreases as one
proceeds to higher temperatures, indicating that there is a thermodynamic
instability and that the canonical ensemble is ill-defined. For certain limits
of the black hole solutions, we exhibit explicit non-linear sigma models
involving a linear dilaton. In other limits we find extremal non-BPS solutions
which may have some relevance to string cosmology.Comment: 53 pages, 21 figures, latex. v2: slightly improved figure
Several specific and nonspecific responses of the human and animal body to ship noise
The effect of noise on cargo boats on a long voyage differs considerably from the effect of noise in factories and in service industries. The peculiarities of the effect of round-the-clock noises at sea at 55 to 85 decibels, typical for cargo boats, were studied in white rats in the laboratory and aboard ship (each of the experiments lasted three months) and in young naval cadets and experienced seamen on voyages lasting one, two, and three months. The findings helped to derive health standards for maximum admissible noise level at sea
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