244 research outputs found
Three-boson problem at low energy and Implications for dilute Bose-Einstein condensates
It is shown that the effective interaction strength of three bosons at small
collision energies can be extracted from their wave function at zero energy. An
asymptotic expansion of this wave function at large interparticle distances is
derived, from which is defined a quantity named three-body scattering
hypervolume, which is an analog of the two-body scattering length. Given any
finite-range interaction potentials, one can thus predict the effective
three-body force from a numerical solution of the Schr\"{o}dinger equation. In
this way the constant for hard-sphere bosons is computed, leading to the
complete result for the ground state energy per particle of a dilute
Bose-Einstein condensate (BEC) of hard spheres to order , where
is the number density. Effects of are also demonstrated in the three-body
energy in a finite box of size , which is expanded to the order ,
and in the three-body scattering amplitude in vacuum. Another key prediction is
that there is a violation of the effective field theory (EFT) in the condensate
fraction in dilute BECs, caused by short-range physics. EFT predictions for the
ground state energy and few-body scattering amplitudes, however, are
corroborated.Comment: 24 pages, no figur
Correlation of high energy muons with primary composition in extensive air shower
An experimental investigation of high energy muons above 200 GeV in extensive air showers has been made for studying high energy interaction and primary composition of cosmic rays of energies in the range 10 to the 14th power approx. 10 to the 15th power eV. The muon energies are estimated from the burst sizes initiated by the muons in the rock, which are measured by four layers of proportional counters, each of area 5 x 2.6 sq m, placed at 30 m.w.e. deep, Funasaka tunnel vertically below the air shower array. These results are compared with Monte Carlo simulations based on the scaling model and the fireball model for two primary compositions, all proton and mixed
Gravitational Wave Spectrum in Inflation with Nonclassical States
The initial quantum state during inflation may evolve to a highly squeezed
quantum state due to the amplification of the time-dependent parameter,
, which may be the modified dispersion relation in
trans-Planckian physics. This squeezed quantum state is a nonclassical state
that has no counterpart in the classical theory. We have considered the
nonclassical states such as squeezed, squeezed coherent, and squeezed thermal
states, and calculated the power spectrum of the gravitational wave
perturbation when the mode leaves the horizon.Comment: 21 page
VERTICAL AND HORIZONTAL FORCES DURING CUTIING IN BASKETBALL UNDER DIFFERENT CONDITIONS
The purpose of this study is to evaluate ground reaction force responses in professional basketball athletes while executing this sport's typical cutting maneuver with and without ankle bracing: taping, aircast-type orthosis and basketball shoes. Eight athletes were dynamically analyzed during a basketball cutting maneuver with a force platform. We collected vertical and medial-lateral forces under these three conditions and analyzed force peaks of foot contact with the ground and propulsion and growth gradient for these forces. Results show that bracing did not significantly change Fymax1 and GCFymax1; significantly reduced Fymax2 and GG Fymax2. With respect to the medial-lateral component, there were no significant differences in relation to force magnitudes between the three study conditions. However, GG Fzmax1 was significantly greater for the sport shoe condition than for the taping condition. Bracing decreased ground reaction force at some instances, but increased in others
Ulam type stability problems for alternative homomorphisms
We introduce an alternative homomorphism with respect to binary operations and investigate the Ulam type stability problem for such a mapping. The obtained results apply to Ulam type stability problems for several important functional equations.ArticleJOURNAL OF INEQUALITIES AND APPLICATIONS. 2014:228 (2014)journal articl
An initial event in insect innate immune response: structural and biological studies of interactions between β-1,3-glucan and the N-terminal domain of β-1,3-glucan recognition protein
In response to invading microorganisms, insect β-1,3-glucan recognition protein (βGRP), a soluble receptor in the hemolymph, binds to the surfaces of bacteria and fungi and activates serine protease cascades that promote destruction of pathogens by means of melanization or expression of antimicrobial peptides. Here we report on the NMR solution structure of the N-terminal domain of βGRP (N-βGRP) from Indian meal moth (Plodia interpunctella), which is sufficient to activate the prophenoloxidase (proPO) pathway resulting in melanin formation. NMR and isothermal calorimetric titrations of N-βGRP with laminarihexaose, a glucose hexamer containing β-1,3 links, suggest a weak binding of the ligand. However, addition of laminarin, a glucose polysaccharide (~ 6 kDa) containing β-1,3 and β-1,6 links that activates the proPO pathway, to N-βGRP results in the loss of NMR cross-peaks from the backbone 15N-1H groups of the protein, suggesting the formation of a large complex. Analytical ultra centrifugation (AUC) studies of formation of N-βGRP:laminarin complex show that ligand-binding induces sel-fassociation of the protein:carbohydrate complex into a macro structure, likely containing six protein and three laminarin molecules (~ 102 kDa). The macro complex is quite stable, as it does not undergo dissociation upon dilution to sub-micromolar concentrations. The structural model thus derived from the present studies for N-βGRP:laminarin complex in solution differs from the one in which a single N-βGRP molecule has been proposed to bind to a triple helical form of laminarin on the basis of an X-ray crystallographic structure of N-βGRP:laminarihexaose complex [Kanagawa, M., Satoh, T., Ikeda, A., Adachi, Y., Ohno, N., and Yamaguchi, Y. (2011) J. Biol. Chem. 286, 29158-29165]. AUC studies and phenoloxidase activation measurements carried out with the designed mutants of N-βGRP indicate that electrostatic interactions involving Asp45, Arg54, and Asp68 between the ligand-bound protein molecules contribute in part to the stability of N-βGRP:laminarin macro complex and that a decreased stability is accompanied by a reduced activation of the proPO pathway. Increased β-1,6 branching in laminarin also results in destabilization of the macro complex. These novel findings suggest that ligand-induced self-association of βGRP:β-1,3-glucan complex may form a platform on a microbial surface for recruitment of downstream proteases, as a means of amplification of the initial signal of pathogen recognition for the activation of the proPO pathway
The Degenerate Parametric Oscillator and Ince's Equation
We construct Green's function for the quantum degenerate parametric
oscillator in terms of standard solutions of Ince's equation in a framework of
a general approach to harmonic oscillators. Exact time-dependent wave functions
and their connections with dynamical invariants and SU(1,1) group are also
discussed.Comment: 10 pages, no figure
MSSM Higgs sector CP violation at photon colliders: Revisited
We present a comprehensive analysis on the MSSM Higgs sector CP violation at
photon colliders including the chargino contributions as well as the
contributions of other charged particles. The chargino loop contributions can
be important for the would-be CP odd Higgs production at photon colliders.
Polarization asymmetries are indispensable in determining the CP properties of
neutral Higgs bosons.Comment: 24 pages, 40 figure
Advances in perturbative thermal field theory
The progress of the last decade in perturbative quantum field theory at high
temperature and density made possible by the use of effective field theories
and hard-thermal/dense-loop resummations in ultrarelativistic gauge theories is
reviewed. The relevant methods are discussed in field theoretical models from
simple scalar theories to non-Abelian gauge theories including gravity. In the
simpler models, the aim is to give a pedagogical account of some of the
relevant problems and their resolution, while in the more complicated but also
more interesting models such as quantum chromodynamics, a summary of the
results obtained so far are given together with references to a few most recent
developments and open problems.Comment: 84 pages, 18 figues, review article submitted to Reports on Progress
in Physics; v2, v3: minor additions and corrections, more reference
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