1,557 research outputs found
BRST approach to Lagrangian construction for bosonic continuous spin field
We formulate the conditions defining the irreducible continuous spin
representation of the four-dimensional Poincar\'e group based on spin-tensor
fields with dotted and undotted indices. Such a formulation simplifies analysis
of the Bargmann-Wigner equations and reduces the number of equations from four
to three. Using this formulation we develop the BRST approach and derive the
covariant Lagrangian for the continuous spin fields.Comment: 10 pages, v2 references adde
Quantum correction to tiny vacuum expectation value in two Higgs doublet model for Dirac neutrino mass
We study a Dirac neutrino mass model of Davidson and Logan. In the model, the
smallness of the neutrino mass is originated from the small vacuum expectation
value of the second Higgs of two Higgs doublets. We study the one loop
effective potential of the Higgs sector and examine how the small vacuum
expectation is stable under the radiative correction. By deriving formulae of
the radiative correction, we numerically study how large the one loop
correction is and show how it depends on the quadratic mass terms and quartic
couplings of the Higgs potential. The correction changes depending on the
various scenarios for extra Higgs mass spectrum.Comment: 27 pages,5 figures. The version corresponds to the revised one
accepted in PRD. In version 4, we have corrected errors of Fig.5 which
reflects the errata of PRD versio
Alfven seismic vibrations of crustal solid-state plasma in quaking paramagnetic neutron star
Magneto-solid-mechanical model of two-component, core-crust, paramagnetic
neutron star responding to quake-induced perturbation by differentially
rotational, torsional, oscillations of crustal electron-nuclear solid-state
plasma about axis of magnetic field frozen in the immobile paramagnetic core is
developed. Particular attention is given to the node-free torsional
crust-against-core vibrations under combined action of Lorentz magnetic and
Hooke's elastic forces; the damping is attributed to Newtonian force of shear
viscose stresses in crustal solid-state plasma. The spectral formulae for the
frequency and lifetime of this toroidal mode are derived in analytic form and
discussed in the context of quasi-periodic oscillations of the X-ray outburst
flux from quaking magnetars. The application of obtained theoretical spectra to
modal analysis of available data on frequencies of oscillating outburst
emission suggests that detected variability is the manifestation of crustal
Alfven's seismic vibrations restored by Lorentz force of magnetic field
stresses.Comment: 10 pages, 10 figure
Boundary Singularity for Thermal Transpiration Problem of the Linearized Boltzmann Equation
We study the boundary singularity of the fluid velocity for the thermal transpiration problem in the kinetic theory. Logarithmic singularity has been demonstrated through the asymptotic and computational analysis. The goal of this paper is to confirm this logarithmic singularity through exact analysis. We use an iterated scheme, with the “gain” part of the collision operator as a source. The iterated scheme is appropriate for large Knudsen numbers considered here and yields an explicit leading term
Singularity of the Velocity Distribution Function in Molecular Velocity Space
We study the boundary singularity of the solutions to the Boltzmann equation in the kinetic theory. The solution has a jump discontinuity in the microscopic velocity ζ on the boundary and a secondary singularity of logarithmic type around the velocity tangential to the boundary, ζn∼0-, where ζn is the component of molecular velocity normal to the boundary, pointing to the gas. We demonstrate this secondary singularity by obtaining an asymptotic formula for the derivative of the solution on the boundary with respect to ζnn that diverges logarithmically when ζn∼0-. Our study is for the thermal transpiration problem between two plates for the hard sphere gases with sufficiently large Knudsen number and with the diffuse reflection boundary condition. The solution is constructed and its singularity is studied by an iteration procedure
Periostin and cancer
Periostin is a secreted protein that shares a structural homology to the axon guidance protein fasciclin I (FAS1) in insects and was originally named as osteoblast-specific factor-2 (Osf2). Periostin is particularly highly homologus to ßig-h3, which promotes cell adhesion and spreading of fibroblasts. It has recently been reported that Periostin was frequently overexpressed in various types of human cancers. Although the detailed function of Periostin is still unclear, Periostin-integrin interaction through FAS1 domain is thought to be involved in tumor development. In addition, Periostin stimulates metastatic growth by promoting cancer cell survival, invasion and angiogenesis. Therefore, Periostin can be a useful marker to predict the behavior of cancer. This review summarizes the recent understanding of Periostin roles in tumor development and speculates on the usefulness of Periostin as a therapeutic and diagnostic target for cancer
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