182 research outputs found
On Wilson Criterion
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
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
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)
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
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 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
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
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.ΠΠΈΠΊΠΎΡΠΈΡΡΠ°Π½Π½Ρ Π±ΡΠΎΠΏΠ°Π»ΠΈΠ²Π° ΠΌΠΎΠΆΠ΅ ΡΡΡΠΎΡΠ½ΠΎ Π·Π½ΠΈΠ·ΠΈΡΠΈ Π΅ΠΌΡΡΡΡ ΠΏΠ°ΡΠ½ΠΈΠΊΠΎΠ²ΠΈΡ
Π³Π°Π·ΡΠ² ΡΠ° ΡΠΊΠΎΡΠΎΡΠΈΡΠΈ ΠΊΡΠ»ΡΠΊΡΡΡΡ Π²ΠΈΠΊΠΎΠΏΠ½ΠΎΠ³ΠΎ ΠΏΠ°Π»ΠΈΠ²Π°, ΡΠΎ ΡΠΏΠ°Π»ΡΡΡΡΡΡ. ΠΠ°ΠΉΠ±ΡΠ»ΡΡ ΠΏΠΎΡΠΈΡΠ΅Π½ΠΈΠΌΠΈ ΡΠ° ΡΠ°ΠΊΠΈΠΌΠΈ, ΡΠΎ Π·Π½Π°ΠΉΡΠ»ΠΈ ΠΊΠΎΠΌΠ΅ΡΡΡΠΉΠ½Π΅ Π·Π°ΡΡΠΎΡΡΠ²Π°Π½Π½Ρ, Π²ΠΈΠ΄Π°ΠΌΠΈ Π±ΡΠΎΠΏΠ°Π»ΠΈΠ²Π° Ρ Π±ΡΠΎΠ΅ΡΠ°Π½ΠΎΠ» ΡΠ° Π±ΡΠΎΠ΄ΠΈΠ·Π΅Π»Ρ Π· ΡΡ
ΠΏΠΎΡ
ΡΠ΄Π½ΠΈΠΌΠΈ. ΠΠ°ΡΡΠΎΡΡΠ²Π°Π½Π½Ρ Π±ΡΠΎΠ΄ΠΈΠ·Π΅Π»Ρ Ρ
Π°ΡΠ°ΠΊΡΠ΅ΡΠΈΠ·ΡΡΡΡΡΡ Π½Π°ΠΉΠ±ΡΠ»ΡΡ Π°ΠΊΡΠΈΠ²Π½ΠΎ Π·ΡΠΎΡΡΠ°ΡΡΠΈΠΌ ΡΠΈΠ½ΠΊΠΎΠ²ΠΈΠΌ ΠΏΠΎΠΏΠΈΡΠΎΠΌ, Π° ΠΠ²ΡΠΎΠΏΠ΅ΠΉΡΡΠΊΠ° Π±ΡΠΎΠ΄ΠΈΠ·Π΅Π»ΡΠ½Π° ΡΠ½Π΄ΡΡΡΡΡΡ Ρ ΡΡΠ°Π±ΡΠ»ΡΠ½ΠΎΡ Π· ΡΡΡΡΡΠ²ΠΈΠΌ ΠΏΠΎΡΡΡΠΉΠ½ΠΈΠΌ Π·ΡΠΎΡΡΠ°Π½Π½ΡΠΌ Π²ΠΈΡΠΎΠ±Π½ΠΈΡΡΠ²Π°. ΠΠ»Ρ Π·Π°Π±Π΅Π·ΠΏΠ΅ΡΠ΅Π½Π½Ρ ΡΠΈΡΠΎΠΊΠΎΠΌΠ°ΡΡΡΠ°Π±Π½ΠΎΠ³ΠΎ, Π½Π° ΡΠ²ΡΡΠΎΠ²ΠΎΠΌΡ ΡΡΠ²Π½Ρ, Π·Π°ΡΡΠΎΡΡΠ²Π°Π½Π½Ρ Π±ΡΠΎΠΏΠ°Π»ΠΈΠ², ΠΎΡΠΎΠ±Π»ΠΈΠ²ΠΎ Π² ΠΊΡΠ°ΡΠ½Π°Ρ
, ΡΠΎ ΡΠΎΠ·Π²ΠΈΠ²Π°ΡΡΡΡΡ, Π΄Π΅ Π΅ΠΌΡΡΡΡ ΠΏΠ°ΡΠ½ΠΈΠΊΠΎΠ²ΠΈΡ
Π³Π°Π·ΡΠ² Π²Π½Π°ΡΠ»ΡΠ΄ΠΎΠΊ Π²ΠΈΠΊΠΎΡΠΈΡΡΠ°Π½Π½Ρ Π²ΠΈΠΊΠΎΠΏΠ½ΠΈΡ
ΠΏΠ°Π»ΠΈΠ² Π΅ΠΊΡΠΏΠΎΠ½Π΅Π½ΡΡΠΉΠ½ΠΎ Π·ΡΠΎΡΡΠ°Ρ, Π²ΠΊΡΠ°ΠΉ Π½Π΅ΠΎΠ±Ρ
ΡΠ΄Π½ΠΈΠΌ Ρ ΠΌΡΠΆΠ½Π°ΡΠΎΠ΄Π½Π΅ ΡΠΏΡΠ²ΡΠΎΠ±ΡΡΠ½ΠΈΡΡΠ²ΠΎ. Π£ ΡΡΠ°ΡΡΡ ΠΎΠ±Π³ΠΎΠ²ΠΎΡΡΡΡΡΡΡ ΠΏΠΈΡΠ°Π½Π½Ρ ΠΏΡΠΎΠΌΠΈΡΠ»ΠΎΠ²ΠΎΠ³ΠΎ Π²ΠΈΡΠΎΠ±Π½ΠΈΡΡΠ²Π° Π±ΡΠΎΠΏΠ°Π»ΠΈΠ²Π°, ΡΡΠ½Π°Π½ΡΠΎΠ²ΠΎΠ³ΠΎ ΡΡΠΈΠΌΡΠ»ΡΠ²Π°Π½Π½Ρ, Π·Π°ΠΊΠΎΠ½ΠΎΠ΄Π°Π²ΡΠΎΡ Π΄ΡΡΠ»ΡΠ½ΠΎΡΡΡ, ΡΠ½Π²Π΅ΡΡΠΈΡΡΠΉΠ½ΠΎΠ³ΠΎ ΠΏΠΎΡΠ΅Π½ΡΡΠ°Π»Ρ ΡΠ° ΡΠ½.ΠΡΠΏΠΎΠ»ΡΠ·ΠΎΠ²Π°Π½ΠΈΠ΅ Π±ΠΈΠΎΡΠΎΠΏΠ»ΠΈΠ²Π° ΠΌΠΎΠΆΠ΅Ρ ΡΡΡΠ΅ΡΡΠ²Π΅Π½Π½ΠΎ ΡΠ½ΠΈΠ·ΠΈΡΡ ΡΠΌΠΈΡΡΠΈΡ ΠΏΠ°ΡΠ½ΠΈΠΊΠΎΠ²ΡΡ
Π³Π°Π·ΠΎΠ² ΠΈ ΡΠΎΠΊΡΠ°ΡΠΈΡΡ ΠΊΠΎΠ»ΠΈΡΠ΅ΡΡΠ²ΠΎ ΡΠΆΠΈΠ³Π°Π΅ΠΌΡΡ
ΠΈΡΠΊΠΎΠΏΠ°Π΅ΠΌΡΡ
ΡΠΎΠΏΠ»ΠΈΠ². ΠΠ°ΠΈΠ±ΠΎΠ»Π΅Π΅ ΡΠ°ΡΠΏΡΠΎΡΡΡΠ°Π½Π΅Π½Π½ΡΠΌΠΈ ΠΈ Π½Π°ΡΠ΅Π΄ΡΠΈΠΌΠΈ ΠΊΠΎΠΌΠΌΠ΅ΡΡΠ΅ΡΠΊΠΎΠ΅ ΠΏΡΠΈΠΌΠ΅Π½Π΅Π½ΠΈΠ΅ Π²ΠΈΠ΄Π°ΠΌΠΈ Π±ΠΈΠΎΡΠΎΠΏΠ»ΠΈΠ²Π° ΡΠ²Π»ΡΡΡΡΡ Π±ΠΈΠΎΡΡΠ°Π½ΠΎΠ» ΠΈ Π±ΠΈΠΎΠ΄ΠΈΠ·Π΅Π»Ρ Π½Π°ΡΡΠ΄Ρ Ρ ΠΈΡ
ΠΏΡΠΎΠΈΠ·Π²ΠΎΠ΄Π½ΡΠΌΠΈ. ΠΡΠΈΠΌΠ΅Π½Π΅Π½ΠΈΠ΅ Π±ΠΈΠΎΠ΄ΠΈΠ·Π΅Π»Ρ Ρ
Π°ΡΠ°ΠΊΡΠ΅ΡΠΈΠ·ΡΠ΅ΡΡΡ Π½Π°ΠΈΠ±ΠΎΠ»Π΅Π΅ Π°ΠΊΡΠΈΠ²Π½ΠΎ ΡΠ°ΡΡΡΡΠΈΠΌ ΡΡΠ½ΠΎΡΠ½ΡΠΌ ΡΠΏΡΠΎΡΠΎΠΌ, Π° ΠΠ²ΡΠΎΠΏΠ΅ΠΉΡΠΊΠ°Ρ Π±ΠΈΠΎΠ΄ΠΈΠ·Π΅Π»ΡΠ½Π°Ρ ΠΈΠ½Π΄ΡΡΡΡΠΈΡ ΡΠ²Π»ΡΠ΅ΡΡΡ ΡΡΠ°Π±ΠΈΠ»ΡΠ½ΠΎΠΉ Ρ ΡΡΡΠ΅ΡΡΠ²Π΅Π½Π½ΡΠΌ ΠΏΠΎΡΡΠΎΡΠ½Π½ΡΠΌ ΡΠΎΡΡΠΎΠΌ ΠΏΡΠΎΠΈΠ·Π²ΠΎΠ΄ΡΡΠ²Π°. ΠΠ»Ρ ΠΎΠ±Π΅ΡΠΏΠ΅ΡΠ΅Π½ΠΈΡ ΡΠΈΡΠΎΠΊΠΎΠΌΠ°ΡΡΡΠ°Π±Π½ΠΎΠ³ΠΎ, Π½Π° ΠΌΠΈΡΠΎΠ²ΠΎΠΌ ΡΡΠΎΠ²Π½Π΅, ΠΏΡΠΈΠΌΠ΅Π½Π΅Π½ΠΈΡ Π±ΠΈΠΎΡΠΎΠΏΠ»ΠΈΠ², ΠΎΡΠΎΠ±Π΅Π½Π½ΠΎ Π² ΡΠ°Π·Π²ΠΈΠ²Π°ΡΡΠΈΡ
ΡΡ ΡΡΡΠ°Π½Π°Ρ
, Π³Π΄Π΅ ΡΠΌΠΈΡΡΠΈΡ ΠΏΠ°ΡΠ½ΠΈΠΊΠΎΠ²ΡΡ
Π³Π°Π·ΠΎΠ² Π²ΡΠ»Π΅Π΄ΡΡΠ²ΠΈΠ΅ ΠΈΡΠΏΠΎΠ»ΡΠ·ΠΎΠ²Π°Π½ΠΈΡ ΠΈΡΠΊΠΎΠΏΠ°Π΅ΠΌΡΡ
ΡΠΎΠΏΠ»ΠΈΠ² ΡΠΊΡΠΏΠΎΠ½Π΅Π½ΡΠΈΠ°Π»ΡΠ½ΠΎ Π²ΠΎΠ·ΡΠ°ΡΡΠ°Π΅Ρ, ΠΊΡΠ°ΠΉΠ½Π΅ Π½Π΅ΠΎΠ±Ρ
ΠΎΠ΄ΠΈΠΌΡΠΌ ΡΠ²Π»ΡΠ΅ΡΡΡ ΠΌΠ΅ΠΆΠ΄ΡΠ½Π°ΡΠΎΠ΄Π½ΠΎΠ΅ ΡΠΎΡΡΡΠ΄Π½ΠΈΡΠ΅ΡΡΠ²ΠΎ. Π ΡΡΠ°ΡΡΠ΅ ΠΎΠ±ΡΡΠΆΠ΄Π°ΡΡΡΡ Π²ΠΎΠΏΡΠΎΡΡ ΠΏΡΠΎΠΌΡΡΠ»Π΅Π½Π½ΠΎΠ³ΠΎ ΠΏΡΠΎΠΈΠ·Π²ΠΎΠ΄ΡΡΠ²Π° Π±ΠΈΠΎΡΠΎΠΏΠ»ΠΈΠ²Π°, ΡΠΈΠ½Π°Π½ΡΠΎΠ²ΠΎΠ³ΠΎ ΡΡΠΈΠΌΡΠ»ΠΈΡΠΎΠ²Π°Π½ΠΈΡ, Π·Π°ΠΊΠΎΠ½ΠΎΠ΄Π°ΡΠ΅Π»ΡΠ½ΠΎΠΉ Π΄Π΅ΡΡΠ΅Π»ΡΠ½ΠΎΡΡΠΈ, ΠΈΠ½Π²Π΅ΡΡΠΈΡΠΈΠΎΠ½Π½ΠΎΠ³ΠΎ ΠΏΠΎΡΠ΅Π½ΡΠΈΠ°Π»Π° ΠΈ Π΄Ρ
Reflection of hydrogen and deuterium atoms from the beryllium, carbon, tungsten surfaces
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
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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