5,192 research outputs found
On Bohr-Sommerfeld bases
This paper combines algebraic and Lagrangian geometry to construct a special
basis in every space of conformal blocks, the Bohr-Sommerfeld (BS) basis. We
use the method of [D. Borthwick, T. Paul and A. Uribe, Legendrian distributions
with applications to the non-vanishing of Poincar\'e series of large weight,
Invent. math, 122 (1995), 359-402, preprint hep-th/9406036], whereby every
vector of a BS basis is defined by some half-weighted Legendrian distribution
coming from a Bohr-Sommerfeld fibre of a real polarization of the underlying
symplectic manifold. The advantage of BS bases (compared to bases of theta
functions in [A. Tyurin, Quantization and ``theta functions'', Jussieu preprint
216 (Apr 1999), e-print math.AG/9904046, 32pp.]) is that we can use information
from the skillful analysis of the asymptotics of quantum states. This gives
that Bohr-Sommerfeld bases are unitary quasi-classically. Thus we can apply
these bases to compare the Hitchin connection with the KZ connection defined by
the monodromy of the Knizhnik-Zamolodchikov equation in combinatorial theory
(see, for example, [T. Kohno, Topological invariants for 3-manifolds using
representations of mapping class group I, Topology 31 (1992), 203-230; II,
Contemp. math 175} (1994), 193-217]).Comment: 43 pages, uses: latex2e with amsmath,amsfonts,theore
Special lagrangian fibrations on flag variety
One constructs lagrangian fibrations on the flag variety and proves
that the fibrations are special.Comment: 19 page
Radiation-induced hydrogen transfer in metals
The paper presents processes of hydrogen (deuterium) diffusion and release from hydrogen-saturated condensed matters in atomic, molecular and ionized states under the influence of the electron beam and X-ray radiation in the pre-threshold region. The dependence is described between the hydrogen isotope release intensity and the current density and the electron beam energy affecting sample, hydrogen concentration in the material volume and time of radiation exposure to the sample. The energy distribution of the emitted positive ions of hydrogen isotopes is investigated herein. Mechanisms of radiation-induced hydrogen transfer in condensed matters are suggested
Determination of some parameters of a porous medium-liquid system by the pulsed field gradient NMR
A possibility was considered to estimate the parameter of a porous medium S/Vp, where S and Vp are the surface area and the volume of pores, respectively, as well as the power of nuclear magnetic energy sinks ρ of a porous medium-liquid system by the example of randomly packed glass spheres 53-63 μm in diameter and acetone, water, or decane as a liquid medium. Estimates were made by analyzing the time dependences of the effective self-diffusion coefficient D(t) and P(t), the probability of return of a molecule to its initial position by time t. It was shown that the short-time parts of D(t) dependence allow us to obtain parameters S/Vp and ρ, whereas those of P(t), only the S/Vp, parameter. The values of ρ, obtained from D(t), and from the time of relaxation of longitudinal nuclear magnetization, differ from each other by an order of magnitude. As expected, the value of S/Vp, obtained for a given porous medium, is independent of the nature of introduced liquid
Spin content of constituent quarks and one-spin asymmetries in inclusive processes
We consider mechanism for one-spin asymmetries observed in inclusive hadron
production. The main role belongs to the orbital angular momentum of the
quark-antiquark cloud in the internal structure of constituent quarks. We argue
that the origin of the asymmetries in pion production is a result of retaining
of this internal angular orbital momentum by the perturbative phase of QCD
under transition from the non-perturbative phase. The non-perturbative hadron
structure is based on the results of chiral quark models. PACS number(s):
11.30.Qc, 12.40.Pp, 13.75.Ni, 13.88.+eComment: 21 pages LaTeX + 8 figures (not included
Monitoring vibrations and microdisplacement for "pin on disc" tribology studies
The paper studies the example of applying accelerometers to evaluate tribocoupling vibration characteristics and verification methods in the testing system "pin on disc". Microelectromechanical systems (MEMS) intended for operation over a wide static and spectral ranges were applied. Accelerator spatial track recovery was implemented through the double integration algorithm. In the course of the work, the vibrations occurring through the friction between fluorocarbon and brass alloy LS59-1 under the conditions of dry friction were studied
Experimental and actual values of self-diffusion coefficients of liquids in porous media
Self-diffusion coefficients D*of liquids in porous media, as measured by the pulsed-field gradient NMR method, have been investigated as functions of the interval t 1 between the first and the second radio-frequency pulses (the time of spin dephasing) in the "stimulated echo" pulsed procedure. Experimental D*(t 1) dependences have been shown to be adequately described by the relations of the Fatkullin theory for moderate and short correlation times of spin motion in an internal random Gaussian magnetic field. Actual self-diffusion coefficients and some parameters of the porous media have been estimated. © 2007 Pleiades Publishing, Ltd
Novel features of diffraction at the LHC
Interest and problems in the studies of diffraction at LHC are highlighted.
Predictions for the global characteristics of proton-proton interactions at the
LHC energy are given. Potential discoveries of the antishadow scattering mode
and diffractive scattering conjugated with high-- jets are discussed.Comment: 10 pages, 7 figures, journal version, 1 figure added, extended
introductio
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