Memory Function versus Binary Correlator in Additive Markov Chains

We study properties of the additive binary Markov chain with short and long-range correlations. A new approach is suggested that allows one to express global statistical properties of a binary chain in terms of the so-called memory function. The latter is directly connected with the pair correlator of a chain via the integral equation that is analyzed in great detail. To elucidate the relation between the memory function and pair correlator, some specific cases were considered that may have important applications in different fields.Comment: 31 pages, 1 figur

Catalog of Nearby Isolated Galaxies in the Volume z<0.01

We present a catalog of 520 most isolated nearby galaxies with radial velocities V_LG<3500 km/s covering the entire sky. This population of "space orphans" makes up 4.8% among 10900 galaxies with measured radial velocities. We describe the isolation criterion used to select our sample, called the "Local Orphan Galaxies" (LOG), and discuss their basic optical and HI properties. A half of the LOG catalog is occupied by the Sdm, Im and Ir morphological type galaxies without a bulge. The median ratio M_gas/M_star in the LOG galaxies exceeds 1. The distribution of the catalog galaxies on the sky looks uniform with some signatures of a weak clustering on the scale of about 0.5 Mpc. The LOG galaxies are located in the regions where the mean local density of matter is approximately 50 times lower than the mean global density. We indicate a number of LOG galaxies with distorted structures, which may be the consequence of interaction of isolated galaxies with massive dark objects

Terahertz transverse-magnetic-polarized waves localized on layered superconductor defect in photonic crystals

We theoretically study eigenstates of electromagnetic field inside a one-dimensional photonic crystal containing a defect slab of layered superconductor. Basing on the transfer matrix formalism along with the electrodynamics of Josephson plasma, we obtain the dispersion relations describing the THz electromagnetic modes localized on defect. We consider both symmetric and antisymmetric configuration of defect in photonic crystal. The comparison of the dispersion spectra of the localized states for the layered-superconducting defect and the pure insulating defect reveals the features of the studied system.Теоретически исследованы собственные состояния электромагнитного поля в одномерном фотонном кристалле, содержащем дефектную пластину из слоистого сверхпроводника. Основываясь на методе трансфер-матрицы, с использованием электродинамики джозефсоновской плазмы, получены дисперсионные соотношения, описывающие терагерцевые электромагнитные моды, локализованные на дефекте. Рассмотрены симметричная и антисимметричная конфигурации дефекта в фотонном кристалле. Сравнение дисперсионных спектров локализованных состояний для сверхпроводящего и диэлектрического дефектов позволяет выявить особенности изучаемой системы.Теоретично вивчені власні стани електромагнітного поля в одновимірному фотонному кристалі, що містить дефектну пластину з шаруватого надпровідника. Ґрунтуючись на методі трансфер-матриці, з використанням електродинаміки джозефсонівської плазми, отримані дисперсійні співвідношення, які описують терагерцові електромагнітні моди, що локалізовані на дефекті. Розглядаються симетрична і антисиметричну конфігурації дефекту в фотонному кристалі. Порівняння дисперсійних спектрів локалізованих станів для надпровідного і діелектричного дефектів дозволило виявити особливості системи, що досліджується

Low-temperature dynamical simulation of spin-boson systems

The dynamics of spin-boson systems at very low temperatures has been studied using a real-time path-integral simulation technique which combines a stochastic Monte Carlo sampling over the quantum fluctuations with an exact treatment of the quasiclassical degrees of freedoms. To a large degree, this special technique circumvents the dynamical sign problem and allows the dynamics to be studied directly up to long real times in a numerically exact manner. This method has been applied to two important problems: (1) crossover from nonadiabatic to adiabatic behavior in electron transfer reactions, (2) the zero-temperature dynamics in the antiferromagnetic Kondo region 1/2<K<1 where K is Kondo's parameter.Comment: Phys. Rev. B (in press), 28 pages, 6 figure

Mathematical+Modeling+of+Cooling+High-Temperature+Cylindrical+Workpieces

AbstractThe paper presents the results of modeling the process of cooling a cylindrical metal workpiece made of structural steel by a flowing cooling medium. The authors give a mathematical description of their solution for the problem of convective heat exchange that occurs when a longitudinal water flow is used for cooling. The control volume approach has been used for solving the systems of equations. The parameters of the flow field are calculated by the SIMPLE algorithm. The mathematical model factors in the presence of vapor being generated at the boundary between the high-temperature workpiece and the cooling water flow. It uses the effective vapor volume fraction calculated according to the heat-balance equation. The calculation results obtained by using the proposed model are compared to calculations by a mathematical model that uses criterial equations for determining the boundary conditions on the surface of a high-temperature cylindrical work piece in contact with the water flow. The authors discuss cases of cooling metal workpieces with different initial heating temperatures. The results of the numerical calculations of the heat exchange parameters are analyzed with regard to the time of the cooling process as well as in regard to whether the vapor presence on the cylinder surface is or is not taken into account