1,091,240 research outputs found

    Search for Tracker Potentials in Quintessence Theory

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    We report a significant finding in Quintessence theory that the the scalar fields with tracker potentials have a model-independent scaling behaviour in the expanding universe. So far widely discussed exponential,power law or hyperbolic potentials can simply mimic the tracking behaviour over a limited range of redshift. In the small redshift range where the variation of the tracking parameter Ο΅\epsilon may be taken to be negligible, the differential equation of generic potentials leads to hyperbolic sine and hyperbolic cosine potentials which may approximate tracker field in the present day universe. We have plotted the variation of tracker potential and the equation of state of the tracker field as function of the redshift zz for the model-independent relation derived from tracker field theory; we have also plotted the variation of V(Ξ¦)V(\Phi) in terms of the scalar field Ξ¦\Phi for the chosen hyperbolic cosine function and have compared with the curves obtained by reconstruction of V(Ο•)V(\phi) from the real observational data from the supernovae.Comment: 11 pages, 3 figures, late

    Nuclear bound states of antikaons, or quantized multiskyrmions?

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    The spectrum of strange multibaryons is considered within the chiral soliton model using one of several possible SU(3$ quantization models (the bound state rigid oscillator version). The states with energy below that of antikaon and corresponding nucleus can be interpreted as antikaon-nucleus bound states. In the formal limit of small kaon mass the number of such states becomes large, for real value of this mass there are at least several states. For large values of binding energies interpretation of such states just as antikaon-nuclear bound states becomes more ambiguous.Comment: Corrections, amendments and additions made, references adde

    Nucleon contribution to the induced charge of neutrinos in a matter background and a magnetic field

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    We study the nucleon contribution to the electromagnetic vertex function of neutrinos that propagate in a matter background in the presence of a magnetic field. Starting from the one-loop expression for the corresponding terms of the vertex function, and taking into account the anomalous magnetic coupling of the nucleons, we calculate the B-dependent part of the form factors that determine the induced charge of the neutrino. A formula for the neutrino induced charge is obtained, and it is evaluated for various illustrative situations. The terms due to the nucleons can be important in some cases, depending on the physical conditions of the environment.Comment: revtex4, 13 pages. Contains the minor revisions made in the prd accepted versio

    Active shielding of magnetic field with circular space-time characteristic

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    Aim. The synthesis of two degree of freedom robust two circuit system of active shielding of magnetic field with circular spacetime characteristic, generated by overhead power lines with "triangle" type of phase conductors arrangements for reducing the magnetic flux density to the sanitary standards level and to reducing the sensitivity of the system to plant parameters uncertainty. Methodology. The synthesis is based on the multi-criteria game decision, in which the payoff vector is calculated on the basis of the Maxwell equations quasi-stationary approximation solutions. The game decision is based on the stochastic particles multiswarm optimization algorithms. The initial parameters for the synthesis by system of active shielding are the location of the overhead power lines with respect to the shielding space, geometry and number of shielding coils, operating currents, as well as the size of the shielding space and magnetic flux density normative value, which should be achieved as a result of shielding. The objective of the synthesis is to determine their number, configuration, spatial arrangementand and shielding coils currents, setting algorithm of the control systems as well as the resulting of the magnetic flux density value at the shielding space. Results. Computer simulation and field experimental research results of two degree of freedom robust two circuit system of active shielding of magnetic field, generated by overhead power lines with Β«triangleΒ» type of phase conductors arrangements are given. The possibility of initial magnetic flux density level reducing and system sensitivity reducing to the plant parameters uncertainty is shown. Originality. For the first time the synthesis, theoretical and experimental research of two degree of freedom robust two -circuit t system of active shielding of magnetic field generated by single-circuit overhead power line with phase conductors triangular arrangements carried out. Practical value. Practical recommendations from the point of view of the practical implementation on reasonable choice of the spatial arrangement of two shielding coils of robust two -circuit system of active shielding of the magnetic field with circular space-time characteristic generated by single-circuit overhead power line with phase conductors triangular arrangements are given.ЦСль. Π‘ΠΈΠ½Ρ‚Π΅Π· ΠΊΠΎΠΌΠ±ΠΈΠ½ΠΈΡ€ΠΎΠ²Π°Π½Π½ΠΎΠΉ робастной Π΄Π²ΡƒΡ…ΠΊΠΎΠ½Ρ‚ΡƒΡ€Π½ΠΎΠΉ систСмы Π°ΠΊΡ‚ΠΈΠ²Π½ΠΎΠ³ΠΎ экранирования ΠΌΠ°Π³Π½ΠΈΡ‚Π½ΠΎΠ³ΠΎ поля с ΠΊΡ€ΡƒΠ³ΠΎΠ²ΠΎΠΉ пространствСнно-Π²Ρ€Π΅ΠΌΠ΅Π½Π½ΠΎΠΉ характСристикой, Π³Π΅Π½Π΅Ρ€ΠΈΡ€ΡƒΠ΅ΠΌΠΎΠ³ΠΎ ΠΎΠ΄Π½ΠΎΠΊΠΎΠ½Ρ‚ΡƒΡ€Π½ΠΎΠΉ Π²ΠΎΠ·Π΄ΡƒΡˆΠ½ΠΎΠΉ Π»ΠΈΠ½ΠΈΠ΅ΠΉ элСктропСрСдачи с Ρ‚Ρ€Π΅ΡƒΠ³ΠΎΠ»ΡŒΠ½Ρ‹ΠΌ подвСсом ΠΏΡ€ΠΎΠ²ΠΎΠ΄ΠΎΠ² для сниТСния ΠΈΠ½Π΄ΡƒΠΊΡ†ΠΈΠΈ ΠΌΠ°Π³Π½ΠΈΡ‚Π½ΠΎΠ³ΠΎ поля Π΄ΠΎ уровня санитарных Π½ΠΎΡ€ΠΌ ΠΈ для сниТСния Ρ‡ΡƒΠ²ΡΡ‚Π²ΠΈΡ‚Π΅Π»ΡŒΠ½ΠΎΡΡ‚ΠΈ систСмы ΠΊ нСопрСдСлСнности ΠΏΠ°Ρ€Π°ΠΌΠ΅Ρ‚Ρ€ΠΎΠ² ΠΎΠ±ΡŠΠ΅ΠΊΡ‚Π° управлСния. ΠœΠ΅Ρ‚ΠΎΠ΄ΠΎΠ»ΠΎΠ³ΠΈΡ. Π‘ΠΈΠ½Ρ‚Π΅Π· основан Π½Π° Ρ€Π΅ΡˆΠ΅Π½ΠΈΠΈ ΠΌΠ½ΠΎΠ³ΠΎΠΊΡ€ΠΈΡ‚Π΅Ρ€ΠΈΠ°Π»ΡŒΠ½ΠΎΠΉ стохастичСской ΠΈΠ³Ρ€Ρ‹, Π² ΠΊΠΎΡ‚ΠΎΡ€ΠΎΠΉ Π²Π΅ΠΊΡ‚ΠΎΡ€Π½Ρ‹ΠΉ Π²Ρ‹ΠΈΠ³Ρ€Ρ‹Ρˆ вычисляСтся Π½Π° основании Ρ€Π΅ΡˆΠ΅Π½ΠΈΠΉ ΡƒΡ€Π°Π²Π½Π΅Π½ΠΈΠΉ МаксвСлла Π² квазистационарном ΠΏΡ€ΠΈΠ±Π»ΠΈΠΆΠ΅Π½ΠΈΠΈ. РСшСниС ΠΈΠ³Ρ€Ρ‹ находится Π½Π° основС Π°Π»Π³ΠΎΡ€ΠΈΡ‚ΠΌΠΎΠ² стохастичСской ΠΌΡƒΠ»ΡŒΡ‚ΠΈΠ°Π³Π΅Π½Ρ‚Π½ΠΎΠΉ ΠΎΠΏΡ‚ΠΈΠΌΠΈΠ·Π°Ρ†ΠΈΠΈ ΠΌΡƒΠ»ΡŒΡ‚ΠΈΡ€ΠΎΠ΅ΠΌ частиц. Π˜ΡΡ…ΠΎΠ΄Π½Ρ‹ΠΌΠΈ ΠΏΠ°Ρ€Π°ΠΌΠ΅Ρ‚Ρ€Π°ΠΌΠΈ для синтСза систСмы Π°ΠΊΡ‚ΠΈΠ²Π½ΠΎΠ³ΠΎ экранирования ΡΠ²Π»ΡΡŽΡ‚ΡΡ располоТСниС Π²Ρ‹ΡΠΎΠΊΠΎΠ²ΠΎΠ»ΡŒΡ‚Π½ΠΎΠΉ Π»ΠΈΠ½ΠΈΠΉ элСктропСрСдачи ΠΏΠΎ ΠΎΡ‚Π½ΠΎΡˆΠ΅Π½ΠΈΡŽ ΠΊ экранируСмому пространству, гСомСтричСскиС Ρ€Π°Π·ΠΌΠ΅Ρ€Ρ‹, количСство ΠΏΡ€ΠΎΠ²ΠΎΠ΄ΠΎΠ² ΠΈ Ρ€Π°Π±ΠΎΡ‡ΠΈΠ΅ Ρ‚ΠΎΠΊΠΈ Π»ΠΈΠ½ΠΈΠΈ элСктропСрСдачи, Π° Ρ‚Π°ΠΊΠΆΠ΅ Ρ€Π°Π·ΠΌΠ΅Ρ€Ρ‹ экранируСмого пространства ΠΈ Π½ΠΎΡ€ΠΌΠ°Ρ‚ΠΈΠ²Π½ΠΎΠ΅ Π·Π½Π°Ρ‡Π΅Π½ΠΈΠ΅ ΠΈΠ½Π΄ΡƒΠΊΡ†ΠΈΠΈ ΠΌΠ°Π³Π½ΠΈΡ‚Π½ΠΎΠ³ΠΎ поля, ΠΊΠΎΡ‚ΠΎΡ€ΠΎΠ΅ Π΄ΠΎΠ»ΠΆΠ½ΠΎ Π±Ρ‹Ρ‚ΡŒ достигнуто Π² Ρ€Π΅Π·ΡƒΠ»ΡŒΡ‚Π°Ρ‚Π΅ экранирования. Π—Π°Π΄Π°Ρ‡Π΅ΠΉ синтСза являСтся ΠΎΠΏΡ€Π΅Π΄Π΅Π»Π΅Π½ΠΈΠ΅ количСства, ΠΊΠΎΠ½Ρ„ΠΈΠ³ΡƒΡ€Π°Ρ†ΠΈΠΈ, пространствСнного располоТСния ΠΈ Ρ‚ΠΎΠΊΠΎΠ² ΡΠΊΡ€Π°Π½ΠΈΡ€ΡƒΡŽΡ‰ΠΈΡ… ΠΎΠ±ΠΌΠΎΡ‚ΠΎΠΊ, Π°Π»Π³ΠΎΡ€ΠΈΡ‚ΠΌΠ° Ρ€Π°Π±ΠΎΡ‚Ρ‹ систСмы управлСния, Π° Ρ‚Π°ΠΊΠΆΠ΅ Ρ€Π΅Π·ΡƒΠ»ΡŒΡ‚ΠΈΡ€ΡƒΡŽΡ‰Π΅Π³ΠΎ значСния ΠΈΠ½Π΄ΡƒΠΊΡ†ΠΈΠΈ ΠΌΠ°Π³Π½ΠΈΡ‚Π½ΠΎΠ³ΠΎ поля Π² экранируСмом пространствС. Π Π΅Π·ΡƒΠ»ΡŒΡ‚Π°Ρ‚Ρ‹. ΠŸΡ€ΠΈΠ²ΠΎΠ΄ΡΡ‚ΡΡ Ρ€Π΅Π·ΡƒΠ»ΡŒΡ‚Π°Ρ‚Ρ‹ тСорСтичСских ΠΈ ΠΏΠΎΠ»Π΅Π²Ρ‹Ρ… ΡΠΊΡΠΏΠ΅Ρ€ΠΈΠΌΠ΅Π½Ρ‚Π°Π»ΡŒΠ½Ρ‹Ρ… исслСдований ΠΊΠΎΠΌΠ±ΠΈΠ½ΠΈΡ€ΠΎΠ²Π°Π½Π½ΠΎΠΉ робастной Π΄Π²ΡƒΡ…ΠΊΠΎΠ½Ρ‚ΡƒΡ€Π½ΠΎΠΉ систСмы Π°ΠΊΡ‚ΠΈΠ²Π½ΠΎΠ³ΠΎ экранирования ΠΌΠ°Π³Π½ΠΈΡ‚Π½ΠΎΠ³ΠΎ поля, Π³Π΅Π½Π΅Ρ€ΠΈΡ€ΡƒΠ΅ΠΌΠΎΠ³ΠΎ Π²ΠΎΠ·Π΄ΡƒΡˆΠ½ΠΎΠΉ Π»ΠΈΠ½ΠΈΠ΅ΠΉ элСктропСрСдачи с Ρ‚Ρ€Π΅ΡƒΠ³ΠΎΠ»ΡŒΠ½Ρ‹ΠΌ подвСсом ΠΏΡ€ΠΎΠ²ΠΎΠ΄ΠΎΠ². Показана Π²ΠΎΠ·ΠΌΠΎΠΆΠ½ΠΎΡΡ‚ΡŒ сниТСния уровня ΠΈΠ½Π΄ΡƒΠΊΡ†ΠΈΠΈ исходного ΠΌΠ°Π³Π½ΠΈΡ‚Π½ΠΎΠ³ΠΎ поля Π²Π½ΡƒΡ‚Ρ€ΠΈ экранируСмого пространства ΠΈ сниТСния Ρ‡ΡƒΠ²ΡΡ‚Π²ΠΈΡ‚Π΅Π»ΡŒΠ½ΠΎΡΡ‚ΠΈ систСмы ΠΊ нСопрСдСлСнностям ΠΏΠ°Ρ€Π°ΠΌΠ΅Ρ‚Ρ€ΠΎΠ² ΠΎΠ±ΡŠΠ΅ΠΊΡ‚Π° управлСния. ΠžΡ€ΠΈΠ³ΠΈΠ½Π°Π»ΡŒΠ½ΠΎΡΡ‚ΡŒ. Π’ΠΏΠ΅Ρ€Π²Ρ‹Π΅ ΠΏΡ€ΠΎΠ²Π΅Π΄Π΅Π½Ρ‹ синтСз, тСорСтичСскиС ΠΈ ΡΠΊΡΠΏΠ΅Ρ€ΠΈΠΌΠ΅Π½Ρ‚Π°Π»ΡŒΠ½Ρ‹Π΅ исслСдования ΠΊΠΎΠΌΠ±ΠΈΠ½ΠΈΡ€ΠΎΠ²Π°Π½Π½ΠΎΠΉ робастной Π΄Π²ΡƒΡ…ΠΊΠΎΠ½Ρ‚ΡƒΡ€Π½ΠΎΠΉ систСмы Π°ΠΊΡ‚ΠΈΠ²Π½ΠΎΠ³ΠΎ экранирования ΠΌΠ°Π³Π½ΠΈΡ‚Π½ΠΎΠ³ΠΎ поля, Π³Π΅Π½Π΅Ρ€ΠΈΡ€ΡƒΠ΅ΠΌΠΎΠ³ΠΎ ΠΎΠ΄Π½ΠΎΠΊΠΎΠ½Ρ‚ΡƒΡ€Π½ΠΎΠΉ Π²ΠΎΠ·Π΄ΡƒΡˆΠ½ΠΎΠΉ Π»ΠΈΠ½ΠΈΠ΅ΠΉ элСктропСрСдачи с Ρ‚Ρ€Π΅ΡƒΠ³ΠΎΠ»ΡŒΠ½Ρ‹ΠΌ подвСсом ΠΏΡ€ΠΎΠ²ΠΎΠ΄ΠΎΠ². ΠŸΡ€Π°ΠΊΡ‚ΠΈΡ‡Π΅ΡΠΊΠ°Ρ Ρ†Π΅Π½Π½ΠΎΡΡ‚ΡŒ. ΠŸΡ€ΠΈΠ²ΠΎΠ΄ΡΡ‚ΡΡ практичСскиС Ρ€Π΅ΠΊΠΎΠΌΠ΅Π½Π΄Π°Ρ†ΠΈΠΈ ΠΏΠΎ обоснованному Π²Ρ‹Π±ΠΎΡ€Ρƒ с Ρ‚ΠΎΡ‡ΠΊΠΈ зрСния практичСской Ρ€Π΅Π°Π»ΠΈΠ·Π°Ρ†ΠΈΠΈ пространствСнного располоТСния Π΄Π²ΡƒΡ… ΡΠΊΡ€Π°Π½ΠΈΡ€ΡƒΡŽΡ‰ΠΈΡ… ΠΎΠ±ΠΌΠΎΡ‚ΠΎΠΊ Π΄Π²ΡƒΡ…ΠΊΠΎΠ½Ρ‚ΡƒΡ€Π½ΠΎΠΉ робастной систСмы Π°ΠΊΡ‚ΠΈΠ²Π½ΠΎΠ³ΠΎ экранирования ΠΌΠ°Π³Π½ΠΈΡ‚Π½ΠΎΠ³ΠΎ поля с ΠΊΡ€ΡƒΠ³ΠΎΠ²ΠΎΠΉ пространствСнно-Π²Ρ€Π΅ΠΌΠ΅Π½Π½ΠΎΠΉ характСристикой, создаваСмого ΠΎΠ΄Π½ΠΎΠΊΠΎΠ½Ρ‚ΡƒΡ€Π½ΠΎΠΉ Π²ΠΎΠ·Π΄ΡƒΡˆΠ½ΠΎΠΉ Π»ΠΈΠ½ΠΈΠ΅ΠΉ элСктропСрСдачи с Ρ‚Ρ€Π΅ΡƒΠ³ΠΎΠ»ΡŒΠ½Ρ‹ΠΌ подвСсом ΠΏΡ€ΠΎΠ²ΠΎΠ΄ΠΎΠ²

    Phenomenological theory of phase transitions in epitaxial BaxSr(1-x)TiO3 thin films

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    A phenomenological thermodynamic theory of BaxSr(1-x)TiO3 (BST-x) thin films epitaxially grown on cubic substrates is developed using the Landau-Devonshire approach. The eighth-order thermodynamic potential for BT single crystal and modified fourth-order potential for ST single crystal were used as starting potentials for the end-members of the solid solution with the aim to develop potential of BST-xx solid solution valid at high temperatures. Several coefficients of these potentials for BT were changed to obtain reasonable agreement between theory and experimental phase diagram for BST-x (x > 0.2) solid solutions. For low Ba content we constructed the specific phase diagram where five phases converge at the multiphase point (T_N2 = 47 K, x = 0.028) and all transitions are of the second order. The "concentration-misfit strain" phase diagrams for BST-x thin films at room temperature and "temperature-misfit strain" phase diagrams for particular concentrations are constructed and discussed. Near T_N2 coupling between polarization and structural order parameter in the epitaxial film is modified considerably and large number of new phases not present in the bulk materials appear on the phase diagram.Comment: 8 pages 5 figure

    Sub-SQL Sensitivity via Optical Rigidity in Advanced LIGO Interferometer with Optical Losses

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    The ``optical springs'' regime of the signal-recycled configuration of laser interferometric gravitational-wave detectors is analyzed taking in account optical losses in the interferometer arm cavities. This regime allows to obtain sensitivity better than the Standard Quantum Limits both for a free test mass and for a conventional harmonic oscillator. The optical losses restrict the gain in sensitivity and achievable signal-to-noise ratio. Nevertheless, for parameters values planned for the Advanced LIGO gravitational-wave detector, this restriction is insignificant.Comment: 15 pages, 9 figure

    The HeH+HeH^+ molecular ion in a magnetic field

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    A detailed study of the low-lying electronic states {}^1\Si,{}^3\Si,{}^3\Pi,{}^3\De of the HeH+\rm{HeH}^+ molecular ion in parallel to a magnetic field configuration (when \al-particle and proton are situated on the same magnetic line) is carried out for B=0βˆ’4.414Γ—1013B=0-4.414\times 10^{13} G in the Born-Oppenheimer approximation. The variational method is employed using a physically adequate trial function. It is shown that the parallel configuration is stable with respect to small deviations for \Si-states. The quantum numbers of the ground state depend on the magnetic field strength. The ground state evolves from the spin-singlet {}^1\Si state for small magnetic fields B≲0.5B\lesssim 0.5 a.u. to the spin-triplet {}^3\Si unbound state for intermediate fields and to the spin-triplet strongly bound 3Ξ ^3\Pi state for B≳15B \gtrsim 15 a.u. When the HeH+\rm{HeH}^+ molecular ion exists, it is stable with respect to a dissociation.Comment: 13 pages, 5 figures, 4 table

    Interaction of plane gravitational waves with a Fabry-Perot cavity in the local Lorentz frame

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    We analyze the interaction of plane '+'-polarized gravitational waves with a Fabry-Perot cavity in the local Lorentz frame of the cavity input mirror outside of the range of long-wave approximation with the force of radiation pressure taken into account. The obtained detector response signal is represented as a sum of two parts: (i) the phase shift due to displacement of the movable mirror under the influence of gravitational wave and the force of light pressure, and (ii) the phase shift due to direct interaction of gravitational wave with light wave inside the cavity. We obtain formula for the movable mirror law of motion paying close attention to the phenomena of optical rigidity, radiative friction and direct coupling of gravitational wave to light wave. Some issues concerning the detection of high-frequency gravitational waves and the role of optical rigidity in it are discussed. We also examine in detail special cases of optical resonance and small detuning from it and compare our results with the known ones.Comment: 17 pages, 9 figures; corrected references [7,8,34], added 2 new references (currently [35,36]), added comments on (i) relativistic corrections, (ii) detector angular pattern, (iii) quantized electromagnetic field, increased font in figure

    Fermentation Quality and in Vitro Nutrient Digestibility of Fresh Rice Straw-Based Silage Treated with Lactic Acid Bacteria

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    The aim of the experiment was to evaluate fermentation characteristics and in vitro nutrient digestibility of fresh rice straw-based silage ensiled with addition of epiphytic lactic acid bacteria (LAB) inoculant. The experiment was arranged in a completely randomized design, with 2 Γ— 2 factorial arrangement of treatments. The first factor was the ratio of fresh rice straw (FRS), tofu waste (TW) and cassava waste (CW) consisted of two levels i.e., 40 : 20 : 40 and 40 : 25 : 35, on dry matter (DM) basis). The second factor was the level of LAB inoculant with two levels ie., 0 and 20 mL/kg FM. The treatments were (A) FRS + TW + CW with the ratio of 40 : 20 : 40, without LAB inoculant; (B) FRS + TW + CW with the ratio of 40 : 20 : 40 + LAB inoculant; (C) FRS + TW + CW with the ratio of 40 : 25 : 35, without LAB inoculant; (D) FRS + TW + CW with ratio of 40 : 25 : 35 + LAB inoculant. Results showed that addition of LAB inoculant in silage increased lactic acid concentration (P0.05) on chemical composition, fermentation quality of silage and in vitro digestibility. It was concluded that mixture silage with ratio of 40 : 20 : 40 with the addition of LAB inoculant had the best fermentation quality and nutrient digestibility than other silages
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