7,295 research outputs found
Unparticle Physics in the Moller Scattering
We investigate the virtual effects of vector unparticles in the Moller
scattering. We derive the analytic expression for scattering amplitudes with
unpolarized beams. We obtain 95% confidence level limits on the unparticle
couplings and with integrated luminosity of
and and 500 GeV energies. We show
that limits on are more sensitive than .Comment: 10 pages, 5 figures, 4 table
Birefringence of interferential mirrors at normal incidence Experimental and computational study
In this paper we present a review of the existing data on interferential
mirror birefringence. We also report new measurements of two sets of mirrors
that confirm that mirror phase retardation per reflection decreases when mirror
reflectivity increases. We finally developed a computational code to calculate
the expected phase retardation per reflection as a function of the total number
of layers constituting the mirror. Different cases have been studied and we
have compared computational results with the trend of the experimental data.
Our study indicates that the origin of the mirror intrinsic birefringence can
be ascribed to the reflecting layers close to the substrate.Comment: To be published in Applied Physics
Analytical solutions for two heteronuclear atoms in a ring trap
We consider two heteronuclear atoms interacting with a short-range
potential and confined in a ring trap. By taking the Bethe-ansatz-type
wavefunction and considering the periodic boundary condition properly, we
derive analytical solutions for the heteronuclear system. The eigen-energies
represented in terms of quasi-momentums can then be determined by solving a set
of coupled equations. We present a number of results, which display different
features from the case of identical atoms. Our result can be reduced to the
well-known Lieb-Liniger solution when two interacting atoms have the same
masses.Comment: 6 pages, 6 figure
Surface tension of the isotropic-nematic interface
We present the first calculations of the pressure tensor profile in the
vicinity of the planar interface between isotropic liquid and nematic liquid
crystal, using Onsager's density functional theory and computer simulation.
When the liquid crystal director is aligned parallel to the interface, the
situation of lowest free energy, there is a large tension on the nematic side
of the interface and a small compressive region on the isotropic side. By
contrast, for perpendicular alignment, the tension is on the isotropic side.
There is excellent agreement between theory and simulation both in the forms of
the pressure tensor profiles, and the values of the surface tension.Comment: Minor changes; to appear in Phys. Rev.
Cell adhesion molecule cadherin-6 function in zebrafish cranial and lateral line ganglia development
Cadherins regulate the vertebrate nervous system development. We previously showed that cadherin-6 message (cdh6) was strongly expressed in the majority of the embryonic zebrafish cranial and lateral line ganglia during their development. Here, we present evidence that cdh6 has specific functions during cranial and lateral line ganglia and nerve development. We analyzed the consequences of cdh6 loss-of-function on cranial ganglion and nerve differentiation in zebrafish embryos. Embryos injected with zebrafish cdh6 specific antisense morpholino oligonucleotides (MOs, which suppress gene expression during development; cdh6 morphant embryos) displayed a specific phenotype, including (i) altered shape and reduced development of a subset of the cranial and lateral line ganglia (e.g., the statoacoustic ganglion and vagal ganglion) and (ii) cranial nerves were abnormally formed. These data illustrate an important role for cdh6 in the formation of cranial ganglia and their nerves
An Analytical Study on the Multi-critical Behaviour and Related Bifurcation Phenomena for Relativistic Black Hole Accretion
We apply the theory of algebraic polynomials to analytically study the
transonic properties of general relativistic hydrodynamic axisymmetric
accretion onto non-rotating astrophysical black holes. For such accretion
phenomena, the conserved specific energy of the flow, which turns out to be one
of the two first integrals of motion in the system studied, can be expressed as
a 8 degree polynomial of the critical point of the flow configuration.
We then construct the corresponding Sturm's chain algorithm to calculate the
number of real roots lying within the astrophysically relevant domain of
. This allows, for the first time in literature, to {\it
analytically} find out the maximum number of physically acceptable solution an
accretion flow with certain geometric configuration, space-time metric, and
equation of state can have, and thus to investigate its multi-critical
properties {\it completely analytically}, for accretion flow in which the
location of the critical points can not be computed without taking recourse to
the numerical scheme. This work can further be generalized to analytically
calculate the maximal number of equilibrium points certain autonomous dynamical
system can have in general. We also demonstrate how the transition from a
mono-critical to multi-critical (or vice versa) flow configuration can be
realized through the saddle-centre bifurcation phenomena using certain
techniques of the catastrophe theory.Comment: 19 pages, 2 eps figures, to appear in "General Relativity and
Gravitation
New Charged Dilaton Solutions in 2+1 Dimensions and Solutions with Cylindrical Symmetry in 3+1 Dimensions
We report a new family of solutions to Einstein-Maxwell-dilaton gravity in
2+1 dimensions and Einstein-Maxwell gravity with cylindrical symmetry in 3+1
dimensions. A set of static charged solutions in 2+1 dimensions are obtained by
a compactification of charged solutions in 3+1 dimensions with cylindrical
symmetry. These solutions contain naked singularities for certain values of the
parameters considered. New rotating charged solutions in 2+1 dimensions and 3+1
dimensions are generated treating the static charged solutions as seed metrics
and performing transformations.Comment: Latex. No figure
Degree of entanglement for two qubits
In this paper, we present a measure to quantify the degree of entanglement
for two qubits in a pure state.Comment: 5 page
Hamiltonicity of 3-arc graphs
An arc of a graph is an oriented edge and a 3-arc is a 4-tuple of
vertices such that both and are paths of length two. The
3-arc graph of a graph is defined to have vertices the arcs of such
that two arcs are adjacent if and only if is a 3-arc of
. In this paper we prove that any connected 3-arc graph is Hamiltonian, and
all iterative 3-arc graphs of any connected graph of minimum degree at least
three are Hamiltonian. As a consequence we obtain that if a vertex-transitive
graph is isomorphic to the 3-arc graph of a connected arc-transitive graph of
degree at least three, then it is Hamiltonian. This confirms the well known
conjecture, that all vertex-transitive graphs with finitely many exceptions are
Hamiltonian, for a large family of vertex-transitive graphs. We also prove that
if a graph with at least four vertices is Hamilton-connected, then so are its
iterative 3-arc graphs.Comment: in press Graphs and Combinatorics, 201
Hawking radiation of nonsingular black holes in two dimensions
In this letter we study the process of Hawking radiation of a black hole
assuming the existence of a limiting physical curvature scale. The particular
model is constructed using the Limiting Curvature Hypothesis (LCH) and in the
context of two-dimensional dilaton gravity. The black hole solution exhibits
properties of the standard Schwarzschild solution at large values of the radial
coordinate. However, near the center, the black hole is nonsingular and the
metric becomes that of de Sitter spacetime. The Hawking temperature is
calculated using the method of complex paths. We find that such black holes
radiate eternally and never completely evaporate. The final state is an
eternally radiating relic, near the fundamental scale, which should make a
viable dark matter candidate. We briefly comment on the black hole information
loss problem and the production of such black holes in collider experiments.Comment: 8 pages, 4 figures; minor revisions; references added; version to
appear in JHE
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