9,685 research outputs found

    Canonical-grandcanonical ensemble in-equivalence in Fermi systems?

    Full text link
    I discuss the effects of fermionic condensation in systems of constant density of states. I show that the condensation leads to a correction of the chemical potential and of the Fermi distribution in canonical Fermi systems at low temperatures. This implies that the canonical and grandcanonical ensembles are not equivalent even for Fermi systems.Comment: 4 pages and 1 figur

    Method to solve integral equations of the first kind with an approximate input

    Full text link
    Techniques are proposed for solving integral equations of the first kind with an input known not precisely. The requirement that the solution sought for includes a given number of maxima and minima is imposed. It is shown that when the deviation of the approximate input from the true one is sufficiently small and some additional conditions are fulfilled the method leads to an approximate solution that is necessarily close to the true solution. No regularization is required in the present approach. Requirements on features of the solution at integration limits are also imposed. The problem is treated with the help of an ansatz proposed for the derivative of the solution. The ansatz is the most general one compatible with the above mentioned requirements. The techniques are tested with exactly solvable examples. Inversions of the Lorentz, Stieltjes and Laplace integral transforms are performed, and very satisfactory results are obtained. The method is useful, in particular, for the calculation of quantum-mechanical reaction amplitudes and inclusive spectra of perturbation-induced reactions in the framework of the integral transform approach.Comment: 28 pages, 1 figure; the presentation is somewhat improved; to be published in Phys. Rev.

    Confining ensemble of dyons

    Full text link
    We construct the integration measure over the moduli space of an arbitrary number of N kinds of dyons of the pure SU(N) gauge theory at finite temperatures. The ensemble of dyons governed by the measure is mathematically described by a (supersymmetric) quantum field theory that is exactly solvable and is remarkable for a number of striking features: 1) The free energy has the minimum corresponding to the zero average Polyakov line, as expected in the confining phase; 2)The correlation function of two Polyakov lines exhibits a linear potential between static quarks in any N-ality non-zero representation, with a calculable string tension roughly independent of temperature; 3) The average spatial Wilson loop falls off exponentially with its area and the same string tension; 4) At a critical temperature the ensemble of dyons rearranges and de-confines; 5)The estimated ratio of the critical temperature to the square root of the string tension is in excellent agreement with the lattice data.Comment: 26 pp. Construction of general N-ality = k strings added. The title change

    Fluctuations of the Fermi condensate in ideal gases

    Full text link
    We calculate numerically and analytically the fluctuations of the fermionic condensate and of the number of particles above the condensate for systems of constant density of states. We compare the canonical fluctuations, obtained from the equivalent Bose condensate fluctuation, with the grandcanonical fermionic calculation. The fluctuations of the condensate are almost the same in the two ensembles, with a small correction comming from the total particle number fluctuation in the grandcanonical ensemble. On the other hand the number of particles above the condensate and its fluctuation is insensitive to the choice of ensemble.Comment: 10 pages with 3 figs. IOP styl

    Analog Property Checkers: A Ddr2 Case Study

    Get PDF
    The formal specification component of verification can be exported to simulation through the idea of property checkers. The essence of this approach is the automatic construction of an observer from the specification in the form of a program that can be interfaced with a simulator and alert the user if the property is violated by a simulation trace. Although not complete, this lighter approach to formal verification has been effectively used in software and digital hardware to detect errors. Recently, the idea of property checkers has been extended to analog and mixed-signal systems. In this paper, we apply the property-based checking methodology to an industrial and realistic example of a DDR2 memory interface. The properties describing the DDR2 analog behavior are expressed in the formal specification language stl/psl in form of assertions. The simulation traces generated from an actual DDR2 interface design are checked with respect to the stl/psl assertions using the amt tool. The focus of this paper is on the translation of the official (informal and descriptive) specification of two non-trivial DDR2 properties into stl/psl assertions. We study both the benefits and the current limits of such approach

    On classification of Poisson vertex algebras

    Get PDF
    We describe a conjectural classification of Poisson vertex algebras of CFT type and of Poisson vertex algebras in one differential variable (= scalar Hamiltonian operators)

    Condensation in ideal Fermi gases

    Full text link
    I investigate the possibility of condensation in ideal Fermi systems of general single particle density of states. For this I calculate the probability wN0w_{N_0} of having exactly N0N_0 particles in the condensate and analyze its maxima. The existence of such maxima at macroscopic values of N0N_0 indicates a condensate. An interesting situation occurs for example in 1D systems, where wN0w_{N_0} may have two maxima. One is at N0=0N_0=0 and another one may exist at finite N0N_0 (for temperatures bellow a certain condensation temperature). This suggests the existence of a first order phase transition. % The calculation of wN0w_{N_0} allows for the exploration of ensemble equivalence of Fermi systems from a new perspective.Comment: 8 pages with 1 figure. Will appear in J. Phys. A: Math. Gen. Changes (minor): I updated Ref. [9] and its citation in the text. I introduced citation for figure 1 in the tex

    Auditor Skepticism: Papuan Case

    Full text link
    The current research aimed to know the influence of audit's experience, independence, audit's competence, audit's situation, time budget pressure, and gender of the audit's professional skeptic. This research was conducted at the BPKP agency of Papua, Indonesia. The sample was taken using a purposive sampling method with some criteria. The analysis' technic used regression doubled linear analysis. According to the result of the partial test, it was found that independence, the audit's situation, and gender had a positive influence on the audit's professional skeptic. Audit's experience, audit's competence, and time budget pressure did not influence significantly to the audit's professional skeptic
    corecore