Group-theoretical approach to a non-central extension of the Kepler-Coulomb problem

Bound and scattering states of a non-central extension of the three-dimensional Kepler-Coulomb Hamiltonian are worked out analytically within the framework of the potential groups of the problem, SO(7) for bound states and SO(6,1) for scattering states. In the latter case, the S matrix is calculated by the method of intertwining operators.Comment: 12 pages, to appear in J. Phys. A : Math. Theo

A disagreement-percolation type uniqueness condition for Gibbs states in models with long-range interaction

Cataloged from PDF version of article.We extend a condition for the uniqueness of Gibbs states in terms of percolation in the coupling of two independent realizations to lattice spin models with long-range interactions and a not necessarily unique ground state. © 2014 IOP Publishing Ltd and SISSA Medialab srl

Uniqueness of Gibbs states in one-dimensional antiferromagnetic model with long-range interaction

Cataloged from PDF version of article.Uniqueness of Gibbs states in the one-dimensional antiferromagnetic model with very long-range interaction is established. © 1999 American Institute of Physics

The one-dimensional long-range ferromagnetic Ising model with a periodic external field

Cataloged from PDF version of article.We consider the one-dimensional ferromagnetic Ising model with very long-range interaction under a periodic, biased and weak external field and prove that at sufficiently low temperatures the model has a unique limiting Gibbs state. © 2012 Elsevier B.V. All rights reserved

Determination of the Heat Distribution in the Raw Cotton Packed in the Coil

As a result of experimental studies, a special mathematical model of raw cotton is developed. The effect of density change on the thermal conductivity coefficient is determined. A nonlinear differential equation of heat propagation in coils is obtained. The dependence of the density of raw cotton on the coil height is determined experimentally. The heat flux is intense propagating from denser layers of raw cotton to less dense ones. In a saturated form, the effect of density changes on the propagation of heat is less than in the coils. Pocket spontaneous heating occurs locally with sharp boundaries.An expression is found, which is the general solution of the mathematical model of heat propagation in raw cotton in coils, on the basis of which a number of physical real models can be constructed.The model allows to preliminarily give an estimation of the likely picture of the temperature field in the given microvolumes of raw cotton

Party building in modern Russia (critical remarks)

The article is devoted to the determination of the values of the party system in the process of democratization of Russian society. This study allows to assert that the Russian party system is far from perfect. On the way of its formation are complex problems that can only be overcome through joint efforts of the authorities and society.Статья посвящена определению значения партийной системы в процессе демократизации российского общества. Проведенное исследование позволяет утверждать, что российская партийная система далека от совершенства. На пути ее становления стоят комплексные проблемы, которые могут быть преодолены только совместными усилиями властей и общества

Lie-algebraic interpretation of the maximal superintegrability and exact solvability of the Coulomb-Rosochatius potential in n dimensions

The potential group method is applied to the n-dimensional Coulomb-Rosochatius potential, whose bound states and scattering states are worked out in detail. As far as scattering is concerned, the S-matrix elements are computed by the method of intertwining operators and an integral representation is obtained for the scattering amplitude. It is shown that the maximal superintegrability of the system is due to the underlying potential group and that the 2n-1 constants of motion are related to Casimir operators of subgroups.Comment: 14 pages, 1 figure, to appear in J. Phys. A : Math. Theo

The relationship between phase transitions and percolation in models with ground-state degeneracy

A criterion for the uniqueness of limiting Gibbs states in classical models with unique ground states is formulated. Various applications of this criterion formulated in the terminology of percolation theory are discussed