1,238 research outputs found
The controlled teleportation of an arbitrary two-atom entangled state in driven cavity QED
In this paper, we propose a scheme for the controlled teleportation of an
arbitrary two-atom entangled state
in driven cavity QED.
An arbitrary two-atom entangled state can be teleported perfectly with the help
of the cooperation of the third side by constructing a three-atom GHZ entangled
state as the controlled channel. This scheme does not involve apparent (or
direct) Bell-state measurement and is insensitive to the cavity decay and the
thermal field. The probability of the success in our scheme is 1.0.Comment: 10 page
A Note on Chern-Simons Solitons - a type III vortex from the wall vortex
We study some properties of topological Chern-Simons vortices in 2 + 1
dimensions. As has already been understood in the past, in the large magnetic
flux limit, they are well described by a Chern-Simons domain wall, which has
been compactified on a circle with the symmetric phase inside and the
asymmetric phase on the outside. Our goal is two-fold. First we want to explore
how the tension depends on the magnetic flux discretized by the integer n. The
BPS case is already known, but not much has been explored about the non-BPS
potentials. A generic renormalizable potential has two dimensionless parameters
that can be varied. Variation of only one of them lead to a type I and type II
vortex, very similar to the Abrikosov-Nielsen-Olesen (ANO) case. Variation of
both the parameters leads to a much richer structure. In particular we have
found a new type of vortex, which is type I-like for small flux and then turns
type II-like for larger flux. We could tentatively denote it a type III vortex.
This results in a stable vortex with number of fluxes which can be greater than
one. Our second objective is to study the Maxwell-Chern-Simons theory and and
understand how the large n limit of the CS vortex is smoothly connected with
the large n limit of the ANO vortex.Comment: 27 pages, 17 figures; v2.: references added, subsection 3.2 added,
explanation added in section 2.
Study of an Alternate Mechanism for the Origin of Fermion Generations
In usual extended technicolor (ETC) theories based on the group
, the quarks of charge 2/3 and -1/3 and the charged
leptons of all generations arise from ETC fermion multiplets transforming
according to the fundamental representation. Here we investigate a different
idea for the origin of SM fermion generations, in which quarks and charged
leptons of different generations arise from ETC fermions transforming according
to different representations of . Although this
mechanism would have the potential, {\it a priori}, to allow a reduction in the
value of relative to conventional ETC models, we show that, at least
in simple models, it is excluded by the fact that the technicolor sector is not
asymptotically free or by the appearance of fermions with exotic quantum
numbers which are not observed.Comment: 6 pages, late
Creep behavior of copper-chromium in-situ composite
Creep deformation and fracture behaviors were investigated on a deformation-processed Cu-Cr in-situ composite over a temperature range of 200 °C to 650 °C. It was found that the creep resistance increases significantly with the introduction of Cr fibers into Cu. The stress exponent and the activation energy for creep of the composite at high temperatures (≥400 °C) were observed to be 5.5 and 180 to 216 kJ/mol, respectively. The observation that the stress exponent and the activation energy for creep of the composite at high temperatures (≥400 °C) are close to those of pure Cu suggests that the creep deformation of the composite is dominated by the deformation of the Cu matrix. The high stress exponent at low temperatures (200 °C and 300 °C) is thought be associated with the as-swaged microstructure, which contains elongated dislocation cells and subgrains that are stable and act as strong athermal obstacles at low temperatures. The mechanism of damage was found to be similar for all the creep tests performed, but the distribution and extent of damage were found to be very sensitive to the test temperature
Development of black ice prediction model using GIS-based multi-sensor model validation
Fog, freezing rain, and snow (melt) quickly condense on road surfaces, forming black ice that is difficult to identify and causes major accidents on highways. As a countermeasure to prevent icing car accidents, it is necessary to predict the amount and location of black ice. This study advanced previous models through machine learning and multi-sensor-verified results. Using spatial (hill shade, river system, bridge, and highway) and meteorological (air temperature, cloudiness, vapour pressure, wind speed, precipitation, snow cover, specific heat, latent heat, and solar radiation energy) data from the study area (Suncheon–Wanju Highway in Gurye-gun, Jeollanam-do, South Korea), the amount and location of black ice were modelled based on system dynamics to predict black ice and then simulated with a geographic information system in units of square metres. The intermediate factors calculated as input factors were road temperature and road moisture, modelled using a deep neural network (DNN) and numerical methods. Considering the results of the DNN, the root mean square error was improved by 148.6 % and reliability by 11.43 % compared to a previous study (linear regression). Based on the model results, multiple sensors were buried at four selected points in the study area. The model was compared with sensor data and verified with the upper-tailed test (with a significance level of 0.05) and fast Fourier transform (freezing does not occur when frequency = 0.00001 Hz). Results of the verified simulation can provide valuable data for government agencies like road traffic authorities to prevent traffic accidents caused by black ice
The upstream magnetic field of collisionless GRB shocks: constraint by Fermi-LAT observations
Long-lived >100 MeV emission has been a common feature of most Fermi-LAT
detected gamma-ray bursts (GRBs), e.g., detected up to ~10^3s in long GRBs
080916C and 090902B and ~10^2s in short GRB 090510. This emission is consistent
with being produced by synchrotron emission of electrons accelerated to high
energy by the relativistic collisionless shock propagating into the weakly
magnetized medium. Here we show that this high-energy afterglow emission
constrains the preshock magnetic field to satisfy 1(n/1cc)^{9/8}
mG<B<10^2(n/1cc)^{3/8}mG, where n is the preshock density, more stringent than
the previous constraint by X-ray afterglow observations on day scale. This
suggests that the preshock magnetic field is strongly amplified, most likely by
the streaming of high energy shock accelerated particles.Comment: 9 pages, JCAP accepte
Impurity effects on s+g-wave superconductivity in borocarbides Y(Lu)Ni_2B_2C
Recently a hybrid s+g-wave pairing is proposed to describe the experimental
observation for a nodal structure of the superconducting gap in borocarbide
YNiBC and possibly LuNiBC. In this paper the impurity effects
on the s+g-wave superconductivity are studied in both Born and unitarity limit.
The quasiparticle density of states and thermodynamics are calculated. It is
found that the nodal excitations in the clean system are immediately prohibited
by impurity scattering and a finite energy gap increases quickly with the
impurity scattering rate. This leads to an activated behavior in the
temperature dependence of the specific heat. Qualitative agreement with the
experimental results is shown. Comparison with d-wave and some anisotropic
s-wave studied previously is also made.Comment: 6 pages, 6 eps figure
Capicua deficiency induces autoimmunity and promotes follicular helper T cell differentiation via derepression of ETV5
High-affinity antibody production through the germinal centre (GC) response is a pivotal process in adaptive immunity. Abnormal development of follicular helper T (T(FH)) cells can induce the GC response to self-antigens, subsequently leading to autoimmunity. Here we show the transcriptional repressor Capicua/CIC maintains peripheral immune tolerance by suppressing aberrant activation of adaptive immunity. CIC deficiency induces excessive development of T(FH) cells and GC responses in a T-cell-intrinsic manner. ETV5 expression is derepressed in Cic null T(FH) cells and knockdown of Etv5 suppresses the enhanced T(FH) cell differentiation in Cic-deficient CD4+ T cells, suggesting that Etv5 is a critical CIC target gene in T(FH) cell differentiation. Furthermore, we identify Maf as a downstream target of the CIC-ETV5 axis in this process. These data demonstrate that CIC maintains T-cell homeostasis and negatively regulates T(FH) cell development and autoimmunity. ? The Author(s) 2017.117Nsciescopu
Non-Abelian Vortices in Supersymmetric Gauge Field Theory via Direct Methods
Vortices in supersymmetric gauge field theory are important constructs in a
basic conceptual phenomenon commonly referred to as the dual Meissner effect
which is responsible for color confinement. Based on a direct minimization
approach, we present a series of sharp existence and uniqueness theorems for
the solutions of some non-Abelian vortex equations governing color-charged
multiply distributed flux tubes, which provide an essential mechanism for
linear confinement. Over a doubly periodic domain, existence results are
obtained under explicitly stated necessary and sufficient conditions that
relate the size of the domain, the vortex numbers, and the underlying physical
coupling parameters of the models. Over the full plane, existence results are
valid for arbitrary vortex numbers and coupling parameters. In all cases,
solutions are unique.Comment: 38 pages, late
Parameterized Complexity of 1-Planarity
We consider the problem of finding a 1-planar drawing for a general graph,
where a 1-planar drawing is a drawing in which each edge participates in at
most one crossing. Since this problem is known to be NP-hard we investigate the
parameterized complexity of the problem with respect to the vertex cover
number, tree-depth, and cyclomatic number. For these parameters we construct
fixed-parameter tractable algorithms. However, the problem remains NP-complete
for graphs of bounded bandwidth, pathwidth, or treewidth.Comment: WADS 201
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