451 research outputs found

    Solving the noncommutative Batalin-Vilkovisky equation

    Full text link
    I show that a summation over ribbon graphs with legs gives the construction of the solutions to the noncommutative Batalin-Vilkovisky equation, including the equivariant version. This generalizes the known construction of A-infinity algebra via summation over ribbon trees. These solutions give naturally the supersymmetric matrix action functionals, which are the gl(N)-equivariantly closed differential forms on the matrix spaces, which were introduced in one of my previous papers "Noncommmutative Batalin-Vilkovisky geometry and Matrix integrals" (arXiv:0912.5484, electronic CNRS preprint hal-00102085(28/09/2006)).Comment: 17 pages, electronic CNRS preprint hal-00464794 (17/03/2010

    Optical Spin Orientation in Strained Superlattices

    Full text link
    Optical orientation in the strained semiconductor superlattices is investigated theoretically. The dependence of the features in spin-polarization spectra on the structure parameters is clarified. The value of polarization in the first polarization maximum in the SL structures is shown to grow with the splitting between the hh- and lh- states of the valence band, the joint strain and confinement effects on the hh1- lh1 splitting being strongly influenced by the tunneling in the barriers. In strained structures with high barriers for the holes initial polarization can exceed 95 %. Calculated polarization spectra are close to the experimental spectra of polarized electron emission.Comment: 20 pages, 8 figure

    Combinatorics and formal geometry of the master equation

    Get PDF
    We give a general treatment of the master equation in homotopy algebras and describe the operads and formal differential geometric objects governing the corresponding algebraic structures. We show that the notion of Maurer-Cartan twisting is encoded in certain automorphisms of these universal objects

    Weak localization of holes in high-mobility heterostructures

    Full text link
    Theory of weak localization is developed for two-dimensional holes in semiconductor heterostructures. Ballistic regime of weak localization where the backscattering occurs from few impurities is studied with account for anisotropic momentum scattering of holes. The transition from weak localization to anti-localization is demonstrated for long dephasing times. For stronger dephasing the conductivity correction is negative at all hole densities due to non-monotonous dependence of the spin relaxation time on the hole wavevector. The anomalous temperature dependent correction to the conductivity is calculated. We show that the temperature dependence of the conductivity is non-monotonous at moderate hole densities.Comment: 5 pages, 4 figure

    Theorem about the number and structure of the singular points n-dimensional dynamical system of population dynamics Lotka-Volterra in context of informational analysis and modeling

    Get PDF
    By elementary methods of combinatorial mathematics and uniqueness of solutions systems of linear algebraic equations for non degenerate cases proved a theorem about the number and structure of the singular points of n-dimensional dynamical system of population a dynamics Lotka-Volterra model. Showed that the number of singular points for this system is equal to 2 and their structure on a combination of zero nand nonzero coordinates coincides with the binomial coefficientsyesBelgorod State Universit

    Problematic of Political Parties Conflict in the Conditions of Competitive Political Market: To the Question of Political Marketing

    Get PDF
    In this article, the authorы explores political parties in the framework of the conflictological paradigm. The researcher notes its close relationship with the paradigm of symbolic interactionism. To understand the nature of the conflict between political parties interacting in a political process, the author operationalizes key concepts and categories: competition, market and market failures, political market, competitive political process, political process, democratic process and components of the political process. As a result of the study, the authors comes to the conclusion that the conflict within the framework of political competition of parties and their interaction (transactions) has its own measure of utility. At the same time, competition and the existence of conflicts between political parties is a competitive, but largely democratic process

    One-dimensional Chern-Simons theory

    Full text link
    We study a one-dimensional toy version of the Chern-Simons theory. We construct its simplicial version which comprises features of a low-energy effective gauge theory and of a topological quantum field theory in the sense of Atiyah.Comment: 37 page

    Characterization of deep impurities in semiconductors by terahertz tunneling ionization

    Get PDF
    Tunneling ionization in high frequency fields as well as in static fields is suggested as a method for the characterization of deep impurities in semiconductors. It is shown that an analysis of the field and temperature dependences of the ionization probability allows to obtain defect parameters like the charge of the impurity, tunneling times, the Huang–Rhys parameter, the difference between optical and thermal binding energy, and the basic structure of the defect adiabatic potentials. Compared to static fields, high frequency electric fields in the terahertz-range offer various advantages, as they can be applied contactlessly and homogeneously even to bulk samples using the intense radiation of a high power pulsed far-infrared laser. Furthermore, impurity ionization with terahertz radiation can be detected as photoconductive signal with a very high sensitivity in a wide range of electric field strengths

    Optical control of spin coherence in singly charged (In,Ga)As/GaAs quantum dots

    Full text link
    Electron spin coherence has been generated optically in n-type modulation doped (In,Ga)As/GaAs quantum dots (QDs) which contain on average a single electron per dot. The coherence arises from resonant excitation of the QDs by circularly-polarized laser pulses, creating a coherent superposition of an electron and a trion state. Time dependent Faraday rotation is used to probe the spin precession of the optically oriented electrons about a transverse magnetic field. Spin coherence generation can be controlled by pulse intensity, being most efficient for (2n+1)pi-pulses.Comment: 5 pages, 4 figure

    Holomorphic potentials for graded D-branes

    Get PDF
    We discuss gauge-fixing, propagators and effective potentials for topological A-brane composites in Calabi-Yau compactifications. This allows for the construction of a holomorphic potential describing the low-energy dynamics of such systems, which generalizes the superpotentials known from the ungraded case. Upon using results of homotopy algebra, we show that the string field and low energy descriptions of the moduli space agree, and that the deformations of such backgrounds are described by a certain extended version of `off-shell Massey products' associated with flat graded superbundles. As examples, we consider a class of graded D-brane pairs of unit relative grade. Upon computing the holomorphic potential, we study their moduli space of composites. In particular, we give a general proof that such pairs can form acyclic condensates, and, for a particular case, show that another branch of their moduli space describes condensation of a two-form.Comment: 47 pages, 7 figure
    corecore