15,251 research outputs found
Vortex solitons in dispersive nonlinear Kerr type media
We have investigated the nonlinear amplitude vector equation governing the
evolution of optical pulses in optical and UV region. We are normalizing this
equation for the cases of different and equal transverse and longitudinal size
of optical pulses, of week and strong dispersion. This gives us the possibility
to reduce the amplitude equation to different nonlinear evolution equations in
the partial cases. For some of these nonlinear equations exact vortex solutions
are found. Conditions for experimental observations of these vortices are
determined.Comment: 28 pages, 9 figures, Late
On the two-loop divergences of the 2-point hypermultiplet supergraphs for , SYM theory
We consider , supersymmetric Yang-Mills theory
formulated in harmonic superspace and analyze the structure of
the two-loop divergences in the hypermultiplet sector. Using the superfield background field method we study the two-point supergraphs
with the hypermultiplet legs and prove that their total contribution to the
divergent part of effective action vanishes off shell.Comment: 8 pages, 2 figure
Supergraph analysis of the one-loop divergences in , and gauge theories
We study the one-loop effective action for
supersymmetric Yang--Mills (SYM) theory with hypermultiplets and SYM theory as a subclass of the former, using the off-shell
formulation of these theories in harmonic superspace. We
develop the corresponding supergraph technique and apply it to compute the
one-loop divergences in the background field method ensuring the manifest gauge
invariance. We calculate the two-point Green functions of the gauge superfield
and the hypermultiplet, as well as the three-point gauge-hypermultipet Green
function. Using these Green functions and exploiting gauge invariance of the
theory, we find the full set of the off-shell one-loop divergent contributions,
including the logarithmic and power ones. Our results precisely match with
those obtained earlier in [1,2] within the proper time superfield method.Comment: 32 pages, 5 figure
Charged analogue of Finch-Skea stars
We present solutions to the Einstein-Maxwell system of equations in
spherically symmetric gravitational fields for static interior spacetimes with
a specified form of the electric field intensity. The condition of pressure
isotropy yields three category of solutions. The first category is expressible
in terms of elementary functions and does not have an uncharged limit. The
second category is given in terms of Bessel functions of half-integer order.
These charged solutions satisfy a barotropic equation of state and contain
Finch-Skea uncharged stars. The third category is obtained in terms of modified
Bessel functions of half-integer order and does not have an uncharged limit.
The physical features of the charged analogue of the Finch-Skea stars are
studied in detail. In particular the condition of causality is satisfied and
the speed of sound does not exceed the speed of light. The physical analysis
indicates that this analogue is a realistic model for static charged
relativistic perfect fluid spheres.Comment: 17 pages, To appear in Int. J. Mod. Phys.
Higgsinoless Supersymmetry and Hidden Gravity
We present a simple formulation of non-linear supersymmetry where superfields
and partnerless fields can coexist. Using this formalism, we propose a
supersymmetric Standard Model without the Higgsino as an effective model for
the TeV-scale supersymmetry breaking scenario. We also consider an application
of the Hidden Local Symmetry in non-linear supersymmetry, where we can
naturally incorporate a spin-two resonance into the theory in a manifestly
supersymmetric way. Possible signatures at the LHC experiments are discussed.Comment: 30 pages, 3 figures, references added, version to appear in JHE
Quantum internal modes of solitons in 1d easy-plane antiferromagnet in strong magnetic field
In presence of a strong external magnetic field the dynamics of solitons in a
one-dimensional easy-plane Heisenberg antiferromagnet exhibits a number of
peculiarities. Dynamics of internal soliton degrees of freedom is essentially
quantum, and they are strongly coupled to the "translational" mode of soliton
movement. These peculiarities lead to considerable changes in the response
functions of the system which can be detected experimentally.Comment: 8 pages, RevTeX, 6 figures, uses psfig.sty, submitted to PR
Full counting statistics for noninteracting fermions: Joint probability distributions
The joint probability distribution in the full counting statistics (FCS) for
noninteracting electrons is discussed for an arbitrary number of initially
separate subsystems which are connected at t=0 and separated at a later time. A
simple method to obtain the leading order long time contribution to the
logarithm of the characteristic function is presented which simplifies earlier
approaches. New explicit results for the determinant involving the scattering
matrices are found. The joint probability distribution for two leads is
discussed for Y-junctions and dots connected to four leads.Comment: 17 pages, 3 figure
Measurement of Counting Statistics of Electron Transport in a Tunnel Junction
We present measurements of the time-dependent fluctuations in electrical
current in a voltage-biased tunnel junction. We were able to simultaneously
extract the first three moments of the tunnel current counting statistics.
Detailed comparison of the second and the third moment reveals that counting
statistics is accurately described by the Poissonian distribution expected for
spontaneous current fluctuations due to electron charge discreteness, realized
in tunneling transport at negligible coupling to environment.Comment: bibliography expande
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