1,432 research outputs found

    Towards Integrability of Topological Strings I: Three-forms on Calabi-Yau manifolds

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    The precise relation between Kodaira-Spencer path integral and a particular wave function in seven dimensional quadratic field theory is established. The special properties of three-forms in 6d, as well as Hitchin's action functional, play an important role. The latter defines a quantum field theory similar to Polyakov's formulation of 2d gravity; the curious analogy with world-sheet action of bosonic string is also pointed out.Comment: 31 page

    Non-Linear Algebra and Bogolubov's Recursion

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    Numerous examples are given of application of Bogolubov's forest formula to iterative solutions of various non-linear equations: one and the same formula describes everything, from ordinary quadratic equation to renormalization in quantum field theory.Comment: LaTex, 21 page

    Reaction of diethyl vinylphosphonate with octyl- and dodecylamines

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    Diethyl vinylphosphonate reacted with octyl- and dodecylamines to give the corresponding addition products which underwent dealkylation via elimination of ethylene molecule with formation of crystalline zwitterionic ethyl 2-(alkylammonio)ethylphoshonates. © 2014 Pleiades Publishing, Ltd

    A method development for improving the stability of vegetable polyphenol complexes for semi-finished minced meat products with antioxidant effect

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    Polyphenolic vegetable complexes are active antioxidants and play an important role in the processes of free radicals quenching in the human body. The aim of the work was to develop an immobilization method as a way for improving the stability of polyphenols in dried cowberry squeezing extract (DCSE) and to develop semi-finished minced meat products with antioxidant effect without changing their nutritional value. Experiments were carried out to study the nutritional value of DCSE. The presence of a large number of polyphenolic compounds in DCSE and a high radical-binding ability of the extract were revealed. Based on the mathematical planning method, an offal paste composition was obtained, which was used to obtain pellets, and the formulation of semi-finished minced meat products with pellets was optimized. It was established that preliminary immobilization of DCSE on offal pellets components allows to increase the level of total antioxidant content in the minced meat. Subsequent heat treatment of semi-finished minced meat products produced from such minced meat showed an increase in stability and, thus, bioavailability of antioxidants and the possibility of obtaining a finished product with antioxidant effect. The antioxidant effect of cowberry squeezing extract in the meat system is proved: accumulation of lipid oxidative decomposition products in the meat system during storage of frozen semi-finished minced meat products was inhibited to a greater extent when using offal pellets with immobilized compounds of cowberry squeezing extract. This work was carried out as part of the State Assignment of the Ministry of Education and Science of the Russian Federation No. 19.5486.2017/BCh and the «Young Scientists of ESSTU‑2019» grant

    Sum Rules and Moments of the Nucleon Spin Structure Functions

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    The nucleon has been used as a laboratory to investigate its own spin structure and Quantum Chromodynamics. New experimental data on nucleon spin structure at low to intermediate momentum transfers combined with existing high momentum transfer data offer a comprehensive picture of the transition region from the {\it confinement} regime of the theory to its {\it asymptotic freedom} regime. Insight for some aspects of the theory is gained by exploring lower moments of spin structure functions and their corresponding sum rules (i.e. the Gerasimov-Drell-Hearn, Bjorken and Burkhardt-Cottingham). These moments are expressed in terms of an operator product expansion using quark and gluon degrees of freedom at moderately large momentum transfers. The sum rules are verified to a good accuracy assuming that no singular behavior of the structure functions is present at very high excitation energies. The higher twist contributions have been examined through the moments evolution as the moments evolution as the momentum transfer varies from higher to lower values. Furthermore, QCD-inspired low-energy effective theories, which explicitly include chiral symmetry breaking, are tested at low momentum transfers. The validity of these theories is further examined as the momentum transfer increases to moderate values. It is found that chiral perturbation calculations agree reasonably well with the first moment of the spin structure function g1g_1 at momentum transfer of 0.1 GeV2^2 but fail to reproduce the neutron data in the case of the generalized polarizability δLT\delta_{LT}.Comment: 21 pages, 4 figures, review for Modern Physics Letters A. Minor modifications in text and improved quality for one figure. Corrected mistakes in section

    Thermo-optic hysteresis with bound states in the continuum

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    We consider thermo-optic hysteresis in a silicon structure supporting bound state in the continuum. Taking into account radiative heat transfer as a major cooling mechanism we constructed a non-linear model describing the optical response. It is shown that the thermo-optic hysteresis can be obtained with low intensities of incident light I01 W/m2I_0\approx 1~\rm{W/m^2} at the red edge of the visible under the critical coupling condition

    Membranes for Topological M-Theory

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    We formulate a theory of topological membranes on manifolds with G_2 holonomy. The BRST charges of the theories are the superspace Killing vectors (the generators of global supersymmetry) on the background with reduced holonomy G_2. In the absence of spinning formulations of supermembranes, the starting point is an N=2 target space supersymmetric membrane in seven euclidean dimensions. The reduction of the holonomy group implies a twisting of the rotations in the tangent bundle of the branes with ``R-symmetry'' rotations in the normal bundle, in contrast to the ordinary spinning formulation of topological strings, where twisting is performed with internal U(1) currents of the N=(2,2) superconformal algebra. The double dimensional reduction on a circle of the topological membrane gives the strings of the topological A-model (a by-product of this reduction is a Green-Schwarz formulation of topological strings). We conclude that the action is BRST-exact modulo topological terms and fermionic equations of motion. We discuss the role of topological membranes in topological M-theory and the relation of our work to recent work by Hitchin and by Dijkgraaf et al.Comment: 22 pp, plain tex. v2: refs. adde

    M-Theory of Matrix Models

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    Small M-theories unify various models of a given family in the same way as the M-theory unifies a variety of superstring models. We consider this idea in application to the family of eigenvalue matrix models: their M-theory unifies various branches of Hermitean matrix model (including Dijkgraaf-Vafa partition functions) with Kontsevich tau-function. Moreover, the corresponding duality relations look like direct analogues of instanton and meron decompositions, familiar from Yang-Mills theory.Comment: 12 pages, contribution to the Proceedings of the Workshop "Classical and Quantum Integrable Systems", Protvino, Russia, January, 200
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