363 research outputs found

    Deterministic growth model of Laplacian charged particle aggregates

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    The results of the computer simulation of the aggregates growth of the similarly charged particles in the framework of deterministic Laplacian growth model on a square lattice are presented. Cluster growth is controlled by three parameters p,E,λ{p, E,\lambda}, where pp - Laplacian growth parameter, EE - energy of a particle sticking to a cluster, λ\lambda - the screening length of electrostatic interactions. The phase diagram of cluster growth is built in the co-ordinates E,λ{E,\lambda}. The zones of different cluster morphology are selected: I-the zone of finite X-like structures,II-the zone of infinite ramified structures, controlled by electrostatic interactions, III-the zone of infinite structures with electrostatic interactions effectively switched off. Simple electrostatic estimations of the locations of the zone boundaries are presented. It is shown that in general case within the zone II the continuous change of DfD_f, controlled by parameters p,E,λ{p, E,\lambda}, takes place. In the degeneration limit when the given model transforms into deterministic version of the Eden model (at p=0p=0), the crossover from linear (Df=1)(D_f=1) to compact (Df=2)(D_f=2) structures is observed when passing through the boundary between the zones I and II.Comment: REVTEX, 3 pages with 4 postscript figure

    Lateral-angular and temporal characteristics of EAS optical radiation

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    Characteristics of the direct and scattered components of electron-photon shower optical radiation for distances R 500 m from the shower core to a detector, allowing for the Cerenkov and fluorescent mechanism of photon generation are presented. The results of calculations are employed to clarify the techniques for determination of the shower parameters detected by both installations registering fluorescent light and those recording Cerenkov light

    MODELING OF ADS-B MESSAGES TRANSMISSION VIA IRIDIUM SATELLITES COMMUNICATION CHANNEL

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    In this article the idea of ADS-B message transmission via communication channel by means of Iridium satellites was considered. The transmission model based on real parameters was created and investigated

    ONTOLOGICAL AND SOCIO-CULTURAL FOUNDATIONS OF THE INTER-GENERATED DISCOURSE IN THE MODERN INFORMATION SOCIETY

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    Purpose of the study: The article is devoted to understanding the problems of intergenerational discourse and its transformation in ontological and sociocultural reality. The paper substantiates the need to maintain the mechanism of accumulation and reproduction of the experience of ancestors. It is shown that the violation of the transfer of knowledge and traditions leads to the distortion or disappearance of universal cultural codes. Methodology: In this article, cultural, demographic, and psychological approaches are used to study the ontological and sociocultural foundations of intergenerational discourse. It is necessary to show the influence of historical and socio-cultural transformations on the characteristics of interaction between generations, to determine the form of transfer and assimilation of experience within the family, to demonstrate the socially significant consequences of the demographic revolution in the modern information society. Main Findings: Having outlined only a few reasons for the intergenerational discourse in the field of translation of sociocultural experience, it can be noted that their combination forms the layer of human life in which historically determined values and ideals of human society are realized, methods of accumulation and transfer of experience that are unique for each historical era, new methods communications. Applications of this study: Research results can be applied in the course of social psychology (today, young people are literally imposed a radical cultural gap with previous generations), social philosophy, cultural studies (the form of transfer of experience within the family) and even demography (large-scale changes in human society, with the destruction of human social instincts). Novelty/Originality of this study: As the initial task of the study, it is supposed to identify historical and sociocultural changes in the field of translation and appropriation of experience, to conduct a cultural analysis that gives a clear idea of the evolution of the methods of interaction between generations. An interdisciplinary approach involves a wider coverage of existing concepts and shows that the patterns of development of human society cannot be reduced only to biological, economic or socio-cultural patterns

    Analytical-numerical methods of calculations of energy and three-dimensional particle distributions in electromagnetic cascades

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    Analytical and numerical methods of calculation of the energy and three dimensional EPS characteristics are reported. The angular and lateral functions of electrons in EPS have been obtained by the Landau and small angle approximations A and B and compared with earlier data. A numerical method of solution of cascade equations for the EPS distribution function moments has been constructed. Considering the equilibrium rms angle as an example, errors appearing when approximating the elementary process cross sections by their asymptotic expressions are analyzed

    Anatomy of Isolated Monopole in Abelian Projection of SU(2) Lattice Gauge Theory

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    We study the structure of the isolated static monopoles in the maximal Abelian projection of SU(2) lattice gluodynamics. Our estimation of the monopole radius is 0.06fm \approx 0.06 fm.Comment: 4 pages, LaTeX2e, 1 figure (epsfig

    Alignment in Gamma-Hadron Families of Cosmic Rays

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    Alignment of main fluxes of energy in a target plane is found in families of cosmic ray particles detected in deep lead X-ray chambers. The fraction of events with alignment is unexpectedly large for families with high energy and large number of hadrons. This can be considered as evidence for the existence of coplanar scattering of secondary particles in interaction of particles with superhigh energy, E0>1016E_0 > 10^{16} eV. Data analysis suggests that production of most aligned groups occurs low above the chamber and is characterized by a coplanar scattering and quasiscaling spectrum of secondaries in the fragmentation region. The most elaborated hypothesis for explanation of alignment is related to the quark-gluon string rupture. However, the problem of theoretical interpretation of our results still remains open.Comment: 15 pages, 2 tables, 6 figures (not included), Stanford University preprint SU-ITP-94-2

    Gluonic phases, vector condensates, and exotic hadrons in dense QCD

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    We study the dynamics in phases with vector condensates of gluons (gluonic phases) in dense two-flavor quark matter. These phases yield an example of dynamics in which the Higgs mechanism is provided by condensates of gauge (or gauge plus scalar) fields. Because vacuum expectation values of spatial components of vector fields break the rotational symmetry, it is naturally to have a spontaneous breakdown both of external and internal symmetries in this case. In particular, by using the Ginzburg-Landau approach, we establish the existence of a gluonic phase with both the rotational symmetry and the electromagnetic U(1) being spontaneously broken. In other words, this phase describes an anisotropic medium in which the color and electric superconductivities coexist. It is shown that this phase corresponds to a minimum of the Ginzburg-Landau potential and, unlike the two-flavor superconducting (2SC) phase, it does not suffer from the chromomagnetic instability. The dual (confinement) description of its dynamics is developed and it is shown that there are light exotic vector hadrons in the spectrum, some of which condense. Because most of the initial symmetries in this system are spontaneously broken, its dynamics is very rich.Comment: 33 pages, RevTeX; v.2: Published PRD versio

    Instanton dominance of topological charge fluctuations in QCD?

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    We consider the local chirality of near-zero eigenvectors from Wilson-Dirac and clover improved Wilson-Dirac lattice operators as proposed recently by Horv\'ath et al. We studied finer lattices and repaired for the loss of orthogonality due to the non-normality of the Wilson-Dirac matrix. As a result we do see a clear double peak structure on lattices with resolutions higher than 0.1 fm. We found that the lattice artifacts can be considerably reduced by exploiting the biorthogonal system of left and right eigenvectors. We conclude that the dominance of instantons on topological charge fluctuations is not ruled out by local chirality measurements.Comment: 10 pages, 6 figure

    Absence of the London limit for the first-order phase transition to a color superconductor

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    We study the effects of gauge-field fluctuations on the free energy of a homogeneous color superconductor in the color-flavor-locked (CFL) phase. Gluonic fluctuations induce a strong first-order phase transition, in contrast to electronic superconductors where this transition is weakly first order. The critical temperature for this transition is larger than the one corresponding to the diquark pairing instability. The physical reason is that the gluonic Meissner masses suppress long-wavelength fluctuations as compared to the normal conducting phase where gluons are massless, which stabilizes the superconducting phase. In weak coupling, we analytically compute the temperatures associated with the limits of metastability of the normal and superconducting phases, as well as the latent heat associated with the first-order phase transition. We then extrapolate our results to intermediate densities and numerically evaluate the temperature of the fluctuation-induced first-order phase transition, as well as the discontinuity of the diquark condensate at the critical point. We find that the London limit of magnetic interactions is absent in color superconductivity.Comment: 14 pages, 5 figure
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