On the Infrared Behavior of the Pressure in Thermal Field Theories

We study non-perturbatively, via the Schwinger-Dyson equations, the leading infrared behavior of the pressure in the ladder approximation. This problem is discussed firstly in the context of a thermal scalar field theory, and the analysis is then extended to the Yang-Mills theory at high temperatures. Using the Feynman gauge, we find a system of two coupled integral equations for the gluon and ghost self-energies, which is solved analytically. The solutions of these equations show that the contributions to the pressure, when calculated in the ladder approximation, are finite in the infrared domain.Comment: 20 pages plus 4 figures available by request, IFUSP/P-100

Autonomous intrusion detection information system

Abstract – Implementation of security arrangements for insecure premises, for example, for temporary exhibitions or infrequent public events, usually results in substantial security personnel costs which can be potentially reduced by employing an easily installable ad hoc intrusion detection information system. In the paper we described the architecture, design and experimental results for a fully prototyped information system that utilizes ultrasonic sensors operating in the pulse echo mode for the perimeter control and ZigBee transceivers for wireless networking. The system consists of inexpensive autonomous sensor nodes with the component cost of less than £25 and a control terminal with a graphical user interface controlled by a touch screen. The nodes are programmed wirelessly to detect intrusion within any user set distance up to the operating distance of the node, and can operate unattended for days. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/2877

Collective Excitations of Massive Dirac Particles in Hot and Dense Medium

The one-loop dispersion equation which defines the collective excitations of the massive Dirac particles in hot and dense quark-gluon medium is obtained in the high temperature limit for the case $m<<T$ and solved explicitly for all |\q| when $\mu=0$. Four well-separated spectrum branches (quasi-particle and quasi-hole excitations) are found and their behaviors for the small and large |\q| are investigated. All calculations are performed using the temperature Green function technique and fixing the Feynman gauge. The gauge dependency of the spectra found are briefly discussed.Comment: 7 pages, latex, no figure

Factors and conditions of functioning and development of modern regional socio-economic systems

Purpose: The purpose of this article is the systemic modernization of scientific ideas relating to the essential factors and conditions of functioning and development of regional socioeconomic systems. Design/Methodology/Approach: To substantiate the article about the possibility of overcoming the socio-economic stagnation and recession of the region's economy based on modernization of research tools and management of local and regional socio-economic processes using modern agglomerative technologies and methods. Findings: Finding lies in clarifying the arrangement, structure and importance of socioeconomic processes, factors and conditions of local, regional and interregional level that determine the effectiveness and sustainability of functioning of the economy. Practical Implications: Are determined by the possibility to use authors' scientific results for audit, evaluation and adjustment of regional socio-economic impacts, measures and development programs, used during designing, forecast and assessment of socio-economic and complex efficiency of local and regional socio-economic activeness in the cities and municipal areas. Originality / Value: It is substantiated by development of the theory and methodology of regional studies of socio-economic factors and conditions that determine long-term prospects of stable functioning and sustainable development of the regional economy on the basis of adaptation of the basic direction of the system and reproduction processes.peer-reviewe

Mathematical analysis of a model of river channel formation.

The study of overland flow of water over an erodible sediment leads to a coupled model describing the evolution of the topographic elevation and the depth of the overland water film. The spatially uniform solution of this model is unstable, and this instability corresponds to the formation of rills, which in reality then grow and coalesce to form large-scale river channels. In this paper we consider the deduction and mathematical analysis of a deterministic model describing river channel formation and the evolution of its depth. The model involves a degenerate nonlinear parabolic equation (satisfied on the interior of the support of the solution) with a super-linear source term and a prescribed constant mass. We propose here a global formulation of the problem (formulated in the whole space, beyond the support of the solution) which allows us to show the existence of a solution and leads to a suitable numerical scheme for its approximation. A particular novelty of the model is that the evolving channel self-determines its own width, without the need to pose any extra conditions at the channel margin

Viscosities of Quark-Gluon Plasmas

The quark and gluon viscosities are calculated in quark-gluon plasmas to leading orders in the coupling constant by including screening. For weakly interaction QCD and QED plasmas dynamical screening of transverse interactions and Debye screening of longitudinal interactions controls the infrared divergences. For strongly interacting plasmas other screening mechanisms taken from lattice calculations are employed. By solving the Boltzmann equation for quarks and gluons including screening the viscosity is calculated to leading orders in the coupling constant. The leading logarithmic order is calculated exactly by a full variational treatment. The next to leading orders are found to be very important for sizable coupling constants as those relevant for the transport properties relevant for quark-gluon plasmas created in relativistic heavy ion collisions and the early universe.Comment: 12 pages + 6 figures, report LBL-3492