2,397 research outputs found
Long-distance behavior of color dependent potentials at finite temperature
SU(3) heavy quark potentials at finite temperature are studied with quenched
lattice QCD using the stochastic gauge-fixing method. In addition to the
standard color average channel, we investigate potentials in singlet
and octet channels. % We obtain clear signals in all cases. The singlet
channel yields an attractive force, while the octet
potential is repulsive; the corresponding color average channel also results in
an attractive force. %As the temperature increases, these forces are weakened
and As the temperature increases, these forces become weak and their variations
are very small; at , % the singlet attractive force is not so
weakened even for long distances. the singlet attractive force survives over . The singlet and octet potentials calculated with this algorithm have
a small gauge dependence when the gauge parameter is changed from 0.6
to 1.3.Comment: 12 pages, 9 figures, typos corrected, to appear in Prog. Theor. Phy
Matrix Factorizations and Representations of Quivers II: type ADE case
We study a triangulated category of graded matrix factorizations for a
polynomial of type ADE. We show that it is equivalent to the derived category
of finitely generated modules over the path algebra of the corresponding Dynkin
quiver. Also, we discuss a special stability condition for the triangulated
category in the sense of T. Bridgeland, which is naturally defined by the
grading.Comment: v2: typos corrected, added an appendix by K.Ued
Incident angle dependence of reactions between graphene and hydrogen atom by molecular dynamics simulation
Incident angle dependence of reactions between graphene and hydrogen atoms
are obtained qualitatively by classical molecular dynamics simulation under the
NVE condition with modified Brenner reactive empirical bond order (REBO)
potential. Chemical reaction depends on two parameters, i.e., polar angle
and azimuthal angle of the incident hydrogen. From the
simulation results, it is found that the reaction rates strongly depend on
polar angle . Reflection rate becomes larger with increasing ,
and the dependence of adsorption rate is also found. The
dependence is caused by three dimensional structure of the small potential
barrier which covers adsorption sites. dependence of penetration rate is
also found for large .Comment: 4 pages, 7 figure
Nonlinear power spectrum in the presence of massive neutrinos: perturbation theory approach, galaxy bias and parameter forecasts
Future or ongoing galaxy redshift surveys can put stringent constraints on
neutrinos masses via the high-precision measurements of galaxy power spectrum,
when combined with cosmic microwave background (CMB) information. In this paper
we develop a method to model galaxy power spectrum in the weakly nonlinear
regime for a mixed dark matter (CDM plus finite-mass neutrinos) model, based on
perturbation theory (PT) whose validity is well tested by simulations for a CDM
model. In doing this we carefully study various aspects of the nonlinear
clustering and then arrive at a useful approximation allowing for a quick
computation of the nonlinear power spectrum as in the CDM case. The nonlinear
galaxy bias is also included in a self-consistent manner within the PT
framework. Thus the use of our PT model can give a more robust understanding of
the measured galaxy power spectrum as well as allow for higher sensitivity to
neutrino masses due to the gain of Fourier modes beyond the linear regime.
Based on the Fisher matrix formalism, we find that BOSS or Stage-III type
survey, when combined with Planck CMB information, gives a precision of total
neutrino mass constraint, sigma(m_nu,tot) 0.1eV, while Stage-IV type survey may
achieve sigma(m_nu,tot) 0.05eV, i.e. more than a 1-sigma detection of neutrino
masses. We also discuss possible systematic errors on dark energy parameters
caused by the neutrino mass uncertainty. The significant correlation between
neutrino mass and dark energy parameters is found, if the information on power
spectrum amplitude is included. More importantly, for Stage-IV type survey, a
best-fit dark energy model may be biased and falsely away from the underlying
true model by more than the 1-sigma statistical errors, if neutrino mass is
ignored in the model fitting.Comment: 33 pages, 11 figure
Strange duality of weighted homogeneous polynomials
We consider a mirror symmetry between invertible weighted homogeneous
polynomials in three variables. We define Dolgachev and Gabrielov numbers for
them and show that we get a duality between these polynomials generalizing
Arnold's strange duality between the 14 exceptional unimodal singularities.Comment: 21 pages, 1 figur
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