183 research outputs found

    On Wilson Criterion

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    U(1) gauge theory with the Villain action on a cubic lattice approximation of three- and four-dimensional torus is considered. The naturally chosen correlation functions converge to the correlation functions of the R-gauge electrodynamics on three- and four-dimensional torus as the lattice spacing approaches zero only for the special scaling. This special scaling depends on a choice of a correlation function system. Another scalings give the degenerate continuum limits. The Wilson criterion for the confinement is ambiguous. The asymptotics of the smeared Wilson loop integral for the large loop perimeters is defined by the density of the loop smearing over a torus which is transversal to the loop plane. When the initial torus radius tends to infinity the correlation functions converge to the correlation functions of the R-gauge Euclidean electrodynamics.Comment: latex, 6 page

    Gravitational cubic interactions for a massive mixed symmetry gauge field

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    In a recent paper arXiv:1107.1872 cubic gravitational interactions for a massless mixed symmetry field in AdS space have been constructed. In the current paper we extend these results to the case of massive field. We work in a Fradkin-Vasiliev approach and use frame-like gauge invariant description for massive field which works in (A)dS spaces with arbitrary values of cosmological constant including flat Minkowski space. In this, massless limit in AdS space coincides with the results of arXiv:1107.1872 while we show that it is impossible to switch on gravitational interaction for massless field in dS space.Comment: 13 page

    Comparison of repulsive interatomic potentials calculated with an all-electron DFT approach with experimental data

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    The interatomic potential determines the nuclear stopping power in materials. Most ion irradiation simulation models are based on the universal-Ziegler-Biersack-Littmark (ZBL) potential (Ziegler et a1.,1983), which, however, is an average and hence may not describe the stopping of all ion-material combinations well. Here we consider pair-specific interatomic potentials determined experimentally and by density functional theory simulations with DMol approach (DMol software, 1997) to choose basic wave functions. The interatomic potentials calculated using the DMol approach demonstrate an unexpectedly good agreement with experimental data. Differences are mainly observed for heavy atom systems, which suggests they can be improved by extending a basis set and more accurately considering the relativistic effects. Experimental data prove that the approach of determining interatomic potentials from quasielastic scattering can be successfully used for modeling collision cascades in ion-solids collisions. The data obtained clearly indicate that the use of any universal potential is limited to internuclear distances R <7 a(f) (a(f) is the Firsov length). (C) 2017 Published by Elsevier B.V.Peer reviewe

    Mixed-symmetry massive fields in AdS(5)

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    Free mixed-symmetry arbitrary spin massive bosonic and fermionic fields propagating in AdS(5) are investigated. Using the light-cone formulation of relativistic dynamics we study bosonic and fermionic fields on an equal footing. Light-cone gauge actions for such fields are constructed. Various limits of the actions are discussed.Comment: v3: 24 pages, LaTeX-2e; typos corrected, footnote 7 and 2 references added, published in Class. Quantum Gra

    Dual Linearised Gravity in Arbitrary Dimensions

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    We construct dual formulation of linearised gravity in first order tetrad formalism in arbitrary dimensions within the path integral framework following the standard duality algorithm making use of the global shift symmetry of the tetrad field. The dual partition function is in terms of the (mixed symmetric) tensor field Ξ¦[Ξ½1Ξ½2...Ξ½dβˆ’3]Ξ½\Phi_{[\nu_{1}\nu_{2}...\nu_{d-3}]\nu} in {\it frame-like} formulation. We obtain in d-dimensions the dual Lagrangian in a closed form in terms of field strength of the dual frame-like field. Next by coupling a source with the (linear) Riemann tensor in d-dimensions, dual generating functional is obtained. Using this an operator mapping between (linear) Riemann tensor and Riemann tensor corresponding to the dual field is derived and we also discuss the exchange of equations of motion and Bianchi identity.Comment: 14 pages, typos corrected, Published version: Class. Quantum Grav. 22(2005)538

    BRST approach to Lagrangian formulation of bosonic totally antisymmeric tensor fields in curved space

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    We apply the BRST approach, previously developed for higher spin field theories, to gauge invariant Lagrangian construction for antisymmetric massive and massless bosonic fields in arbitrary d-dimensional curved space. The obtained theories are reducible gauge models both in massless and massive cases and the order of reducibility grows with the value of the rank of the antisymmetric field. In both the cases the Lagrangians contain the sets of auxiliary fields and possess more rich gauge symmetry in comparison with standard Lagrangian formulation for the antisymmetric fields. This serves additional demonstration of universality of the BRST approach for Lagrangian constructions in various field models.Comment: 12 page

    Biofuel as Alternative Energy Carrier : Current Status, European Policies, Market and Production Level

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    Biofuels could be an appropriate way to reduce green house gas (GHG) emissions and to reduce the amount of fossil fuels burned. Two most common types of biofuels which are being developed and presently available on a commercial basis, are Ethanol and Biodiesel along with their derivatives. Biodiesel is the biofuel with the most rapid rate of market growth. European biodiesel industry is well established with a significant continuous increase in its production. In order to support the use of biodiesel and biofuel World-wide, especially, in developing countries where fossil energy use GHG emission will rise exponentially, there is a utmost necessity for international co-operation. The questions of biofuel industrial production, financial incentives, legislation, investment potential et. al. will be discussed in this publication.Використання Π±Ρ–ΠΎΠΏΠ°Π»ΠΈΠ²Π° ΠΌΠΎΠΆΠ΅ істотно Π·Π½ΠΈΠ·ΠΈΡ‚ΠΈ Π΅ΠΌΡ–ΡΡ–ΡŽ ΠΏΠ°Ρ€Π½ΠΈΠΊΠΎΠ²ΠΈΡ… Π³Π°Π·Ρ–Π² Ρ‚Π° скоротити ΠΊΡ–Π»ΡŒΠΊΡ–ΡΡ‚ΡŒ Π²ΠΈΠΊΠΎΠΏΠ½ΠΎΠ³ΠΎ ΠΏΠ°Π»ΠΈΠ²Π°, Ρ‰ΠΎ ΡΠΏΠ°Π»ΡŽΡ”Ρ‚ΡŒΡΡ. ΠΠ°ΠΉΠ±Ρ–Π»ΡŒΡˆ ΠΏΠΎΡˆΠΈΡ€Π΅Π½ΠΈΠΌΠΈ Ρ‚Π° Ρ‚Π°ΠΊΠΈΠΌΠΈ, Ρ‰ΠΎ знайшли ΠΊΠΎΠΌΠ΅Ρ€Ρ†Ρ–ΠΉΠ½Π΅ застосування, Π²ΠΈΠ΄Π°ΠΌΠΈ Π±Ρ–ΠΎΠΏΠ°Π»ΠΈΠ²Π° Ρ” Π±Ρ–ΠΎΠ΅Ρ‚Π°Π½ΠΎΠ» Ρ‚Π° Π±Ρ–ΠΎΠ΄ΠΈΠ·Π΅Π»ΡŒ Π· Ρ—Ρ… ΠΏΠΎΡ…Ρ–Π΄Π½ΠΈΠΌΠΈ. Застосування біодизСля Ρ…Π°Ρ€Π°ΠΊΡ‚Π΅Ρ€ΠΈΠ·ΡƒΡ”Ρ‚ΡŒΡΡ Π½Π°ΠΉΠ±Ρ–Π»ΡŒΡˆ Π°ΠΊΡ‚ΠΈΠ²Π½ΠΎ Π·Ρ€ΠΎΡΡ‚Π°ΡŽΡ‡ΠΈΠΌ Ρ€ΠΈΠ½ΠΊΠΎΠ²ΠΈΠΌ ΠΏΠΎΠΏΠΈΡ‚ΠΎΠΌ, Π° Π„Π²Ρ€ΠΎΠΏΠ΅ΠΉΡΡŒΠΊΠ° Π±Ρ–ΠΎΠ΄ΠΈΠ·Π΅Π»ΡŒΠ½Π° індустрія Ρ” ΡΡ‚Π°Π±Ρ–Π»ΡŒΠ½ΠΎΡŽ Π· суттєвим постійним зростанням Π²ΠΈΡ€ΠΎΠ±Π½ΠΈΡ†Ρ‚Π²Π°. Для забСзпСчСння ΡˆΠΈΡ€ΠΎΠΊΠΎΠΌΠ°ΡΡˆΡ‚Π°Π±Π½ΠΎΠ³ΠΎ, Π½Π° світовому Ρ€Ρ–Π²Π½Ρ–, застосування Π±Ρ–ΠΎΠΏΠ°Π»ΠΈΠ², особливо Π² ΠΊΡ€Π°Ρ—Π½Π°Ρ…, Ρ‰ΠΎ Ρ€ΠΎΠ·Π²ΠΈΠ²Π°ΡŽΡ‚ΡŒΡΡ, Π΄Π΅ Смісія ΠΏΠ°Ρ€Π½ΠΈΠΊΠΎΠ²ΠΈΡ… Π³Π°Π·Ρ–Π² внаслідок використання Π²ΠΈΠΊΠΎΠΏΠ½ΠΈΡ… ΠΏΠ°Π»ΠΈΠ² СкспонСнційно зростає, Π²ΠΊΡ€Π°ΠΉ Π½Π΅ΠΎΠ±Ρ…Ρ–Π΄Π½ΠΈΠΌ Ρ” ΠΌΡ–ΠΆΠ½Π°Ρ€ΠΎΠ΄Π½Π΅ співробітництво. Π£ статті ΠΎΠ±Π³ΠΎΠ²ΠΎΡ€ΡŽΡŽΡ‚ΡŒΡΡ питання промислового Π²ΠΈΡ€ΠΎΠ±Π½ΠΈΡ†Ρ‚Π²Π° Π±Ρ–ΠΎΠΏΠ°Π»ΠΈΠ²Π°, фінансового ΡΡ‚ΠΈΠΌΡƒΠ»ΡŽΠ²Π°Π½Π½Ρ, Π·Π°ΠΊΠΎΠ½ΠΎΠ΄Π°Π²Ρ‡ΠΎΡ— Π΄Ρ–ΡΠ»ΡŒΠ½ΠΎΡΡ‚Ρ–, інвСстиційного ΠΏΠΎΡ‚Π΅Π½Ρ†Ρ–Π°Π»Ρƒ Ρ‚Π° Ρ–Π½.ИспользованиС Π±ΠΈΠΎΡ‚ΠΎΠΏΠ»ΠΈΠ²Π° ΠΌΠΎΠΆΠ΅Ρ‚ сущСствСнно ΡΠ½ΠΈΠ·ΠΈΡ‚ΡŒ эмиссию ΠΏΠ°Ρ€Π½ΠΈΠΊΠΎΠ²Ρ‹Ρ… Π³Π°Π·ΠΎΠ² ΠΈ ΡΠΎΠΊΡ€Π°Ρ‚ΠΈΡ‚ΡŒ количСство сТигаСмых ископаСмых Ρ‚ΠΎΠΏΠ»ΠΈΠ². НаиболСС распространСнными ΠΈ нашСдшими коммСрчСскоС ΠΏΡ€ΠΈΠΌΠ΅Π½Π΅Π½ΠΈΠ΅ Π²ΠΈΠ΄Π°ΠΌΠΈ Π±ΠΈΠΎΡ‚ΠΎΠΏΠ»ΠΈΠ²Π° ΡΠ²Π»ΡΡŽΡ‚ΡΡ биоэтанол ΠΈ биодизСль наряду с ΠΈΡ… ΠΏΡ€ΠΎΠΈΠ·Π²ΠΎΠ΄Π½Ρ‹ΠΌΠΈ. ΠŸΡ€ΠΈΠΌΠ΅Π½Π΅Π½ΠΈΠ΅ биодизСля характСризуСтся Π½Π°ΠΈΠ±ΠΎΠ»Π΅Π΅ Π°ΠΊΡ‚ΠΈΠ²Π½ΠΎ растущим Ρ€Ρ‹Π½ΠΎΡ‡Π½Ρ‹ΠΌ спросом, Π° ЕвропСйская биодизСльная индустрия являСтся ΡΡ‚Π°Π±ΠΈΠ»ΡŒΠ½ΠΎΠΉ с сущСствСнным постоянным ростом производства. Для обСспСчСния ΡˆΠΈΡ€ΠΎΠΊΠΎΠΌΠ°ΡΡˆΡ‚Π°Π±Π½ΠΎΠ³ΠΎ, Π½Π° ΠΌΠΈΡ€ΠΎΠ²ΠΎΠΌ ΡƒΡ€ΠΎΠ²Π½Π΅, примСнСния Π±ΠΈΠΎΡ‚ΠΎΠΏΠ»ΠΈΠ², особСнно Π² Ρ€Π°Π·Π²ΠΈΠ²Π°ΡŽΡ‰ΠΈΡ…ΡΡ странах, Π³Π΄Π΅ эмиссия ΠΏΠ°Ρ€Π½ΠΈΠΊΠΎΠ²Ρ‹Ρ… Π³Π°Π·ΠΎΠ² вслСдствиС использования ископаСмых Ρ‚ΠΎΠΏΠ»ΠΈΠ² ΡΠΊΡΠΏΠΎΠ½Π΅Π½Ρ†ΠΈΠ°Π»ΡŒΠ½ΠΎ возрастаСт, ΠΊΡ€Π°ΠΉΠ½Π΅ Π½Π΅ΠΎΠ±Ρ…ΠΎΠ΄ΠΈΠΌΡ‹ΠΌ являСтся ΠΌΠ΅ΠΆΠ΄ΡƒΠ½Π°Ρ€ΠΎΠ΄Π½ΠΎΠ΅ сотрудничСство. Π’ ΡΡ‚Π°Ρ‚ΡŒΠ΅ ΠΎΠ±ΡΡƒΠΆΠ΄Π°ΡŽΡ‚ΡΡ вопросы ΠΏΡ€ΠΎΠΌΡ‹ΡˆΠ»Π΅Π½Π½ΠΎΠ³ΠΎ производства Π±ΠΈΠΎΡ‚ΠΎΠΏΠ»ΠΈΠ²Π°, финансового стимулирования, Π·Π°ΠΊΠΎΠ½ΠΎΠ΄Π°Ρ‚Π΅Π»ΡŒΠ½ΠΎΠΉ Π΄Π΅ΡΡ‚Π΅Π»ΡŒΠ½ΠΎΡΡ‚ΠΈ, инвСстиционного ΠΏΠΎΡ‚Π΅Π½Ρ†ΠΈΠ°Π»Π° ΠΈ Π΄Ρ€

    Reflection of hydrogen and deuterium atoms from the beryllium, carbon, tungsten surfaces

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    Particle reflection coefficients for scattering of hydrogen and deuterium atoms from amorphous beryllium, carbon and tungsten were obtained, which are of interest for thermonuclear reactor physics. For the case of deuterium scattering from tungsten the data were also calculated for polycrystalline and crystalline target. The calculations were carried out by two methods: by modeling the trajectories of the incident particles and by using the binary collision approximation. Interaction potentials between hydrogen and helium atoms and the selected materials were calculated in the scope of the density function theory using program DMol for choosing wave functions. The dependence of the reflection coefficient RN on the potential well depth was found. The results demonstrate a good agreement with the available experimental values.Peer reviewe

    Massive Gravity on de Sitter and Unique Candidate for Partially Massless Gravity

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    We derive the decoupling limit of Massive Gravity on de Sitter in an arbitrary number of space-time dimensions d. By embedding d-dimensional de Sitter into d+1-dimensional Minkowski, we extract the physical helicity-1 and helicity-0 polarizations of the graviton. The resulting decoupling theory is similar to that obtained around Minkowski. We take great care at exploring the partially massless limit and define the unique fully non-linear candidate theory that is free of the helicity-0 mode in the decoupling limit, and which therefore propagates only four degrees of freedom in four dimensions. In the latter situation, we show that a new Vainshtein mechanism is at work in the limit m^2\to 2 H^2 which decouples the helicity-0 mode when the parameters are different from that of partially massless gravity. As a result, there is no discontinuity between massive gravity and its partially massless limit, just in the same way as there is no discontinuity in the massless limit of massive gravity. The usual bounds on the graviton mass could therefore equivalently well be interpreted as bounds on m^2-2H^2. When dealing with the exact partially massless parameters, on the other hand, the symmetry at m^2=2H^2 imposes a specific constraint on matter. As a result the helicity-0 mode decouples without even the need of any Vainshtein mechanism.Comment: 30 pages. Some clarifications and references added. New subsection 'Symmetry and Counting in the Full Theory' added. New appendix 'St\"uckelberg fields in the Na\"ive approach' added. Matches version published in JCA
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