105 research outputs found

    Is the Luttinger liquid a new state of matter?

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    We are demonstrating that the Luttinger model with short range interaction can be treated as a type of Fermi liquid. In line with the main dogma of Landau's theory one can define a fermion excitation renormalized by interaction and show that in terms of these fermions any excited state of the system is described by free particles. The fermions are a mixture of renormalized right and left electrons. The electric charge and chirality of the Landau quasi-particle is discussed.Comment: paper 10 pages. This version of the paper will be published in Foundations of Physic

    Nucleotide sequence of the Galleria mellonella nuclear polyhedrosis virus origin of DNA replication

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    AbstractThe initiation sites of the Galleria mellonella L. nuclear polyhedrosis virus (G.m. NPV) DNA replication were revealed. For this purpose SCLd 135 cells permitting the G.m. NPV productive reproduction were transformed by the recombinant plasmids containing the viral genome individual fragments in pRSF 2124 and pBR 322 vectors. It was revealed that 2 of the 32 recombinant plasmids can autonomously replicate in the eucaryotic cells. According to the Maxam-Gilbert method the DNA G.m. NPV fragment (1300 bp) primary structure of pHBR plasmid was determined. The structure analysis revealed the typical regulator signals as in the replicons. The possible regulation mechanisms of the DNA G.m. NPV synthesis initiation was supposed

    Low Density Limit of BCS Theory and Bose-Einstein Condensation of Fermion Pairs

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    We consider the low density limit of a Fermi gas in the BCS approximation. We show that if the interaction potential allows for a two-particle bound state, the system at zero temperature is well approximated by the Gross-Pitaevskii functional, describing a Bose-Einstein condensate of fermion pairs.Comment: LaTeX2e, 17 page

    Probabilistic analysis of the upwind scheme for transport

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    We provide a probabilistic analysis of the upwind scheme for multi-dimensional transport equations. We associate a Markov chain with the numerical scheme and then obtain a backward representation formula of Kolmogorov type for the numerical solution. We then understand that the error induced by the scheme is governed by the fluctuations of the Markov chain around the characteristics of the flow. We show, in various situations, that the fluctuations are of diffusive type. As a by-product, we prove that the scheme is of order 1/2 for an initial datum in BV and of order 1/2-a, for all a>0, for a Lipschitz continuous initial datum. Our analysis provides a new interpretation of the numerical diffusion phenomenon

    Finite-temperature correlations in the one-dimensional trapped and untrapped Bose gases

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    We calculate the dynamic single-particle and many-particle correlation functions at non-zero temperature in one-dimensional trapped repulsive Bose gases. The decay for increasing distance between the points of these correlation functions is governed by a scaling exponent that has a universal expression in terms of observed quantities. This expression is valid in the weak-interaction Gross-Pitaevskii as well as in the strong-interaction Girardeau-Tonks limit, but the observed quantities involved depend on the interaction strength. The confining trap introduces a weak center-of-mass dependence in the scaling exponent. We also conjecture results for the density-density correlation function.Comment: 18 pages, Latex, Revtex

    High-current pulse electron accelerators based on stepped forming lines

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    There presented is a brief review of I-3000, STRAUS, STRAUS-2 and LIA-10M accelerators produced in VNIIEF over the period from 1981 to 1994. All the installations function in the mode of single pulses. Their distinction consists in using the systems of forming high-voltage pulses on the basis of stepped forming lines. Such installations formed of line sections of a similar electrical length with a stepped character of impedance variance provide a high efficiency and as a result of wave processes increase for a several time the output voltage as compared to the charge voltage of lines. The limiting energy of accelerated electrons for the created accelerators lies within the range from 2.3 to 25 MeV, beam current amplitude – from 20 to 50 kA, current pulse width at half-height – from 16 to 40 ns. The basic characteristics of each accelerator are presented

    Moderate deviations via cumulants

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    The purpose of the present paper is to establish moderate deviation principles for a rather general class of random variables fulfilling certain bounds of the cumulants. We apply a celebrated lemma of the theory of large deviations probabilities due to Rudzkis, Saulis and Statulevicius. The examples of random objects we treat include dependency graphs, subgraph-counting statistics in Erd\H{o}s-R\'enyi random graphs and UU-statistics. Moreover, we prove moderate deviation principles for certain statistics appearing in random matrix theory, namely characteristic polynomials of random unitary matrices as well as the number of particles in a growing box of random determinantal point processes like the number of eigenvalues in the GUE or the number of points in Airy, Bessel, and sin\sin random point fields.Comment: 24 page

    Collective excitations of a two-dimensional interacting Bose gas in anti-trap and linear external potentials

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    We present a method of finding approximate analytical solutions for the spectra and eigenvectors of collective modes in a two-dimensional system of interacting bosons subjected to a linear external potential or the potential of a special form u(x,y)=μucosh2x/lu(x,y)=\mu -u \cosh^2 x/l, where μ\mu is the chemical potential. The eigenvalue problem is solved analytically for an artificial model allowing the unbounded density of the particles. The spectra of collective modes are calculated numerically for the stripe, the rare density valley and the edge geometry and compared with the analytical results. It is shown that the energies of the modes localized at the rare density region and at the edge are well approximated by the analytical expressions. We discuss Bose-Einstein condensation (BEC) in the systems under investigations at T0T\ne 0 and find that in case of a finite number of the particles the regime of BEC can be realized, whereas the condensate disappears in the thermodynamic limit.Comment: 10 pages, 2 figures include

    The effect of a small helium addition on the plasma-surface interaction in QSPA

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    The synergistic effects of tungsten exposure to combined hydrogen and helium particle fluxes as well as transient thermal loads need to be extensively studied for implementation of fusion reactor project. The mixture of hydrogen and helium was used as the working gas for plasma stream generation within the QSPA-M accelerator. The parameters of the mixed hydrogen and helium plasma were similar to those of pure hydrogen plasma generated in QSPA-M. It was shown that the small addition of helium (5%) to hydrogen does not strongly influence plasma surface interaction. The influence of the external magnetic field on plasma surface interaction is also discussed.Для реалізації проекту термоядерного реактора необхідно детально вивчити синергетичні ефекти впливу на вольфрам комбінованих потоків частинок водню і гелію, а також перехідних теплових навантажень. Суміш водню та гелію використовувалася в якості робочого газу для генерації плазмових потоків в установці КСПП-M. Параметри воднево-гелієвої плазми в КСПП-M були подібні до параметрів чисто водневої плазми. Показано, що невелике додавання гелію (5%) до водню не має сильного впливу на взаємодію плазми з поверхнею. Обговорено також вплив зовнішнього магнітного поля на взаємодію плазми з поверхнями
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