9,685 research outputs found
Canonical-grandcanonical ensemble in-equivalence in Fermi systems?
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
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
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
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
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
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
I investigate the possibility of condensation in ideal Fermi systems of
general single particle density of states. For this I calculate the probability
of having exactly particles in the condensate and analyze its
maxima. The existence of such maxima at macroscopic values of indicates a
condensate. An interesting situation occurs for example in 1D systems, where
may have two maxima. One is at and another one may exist at
finite (for temperatures bellow a certain condensation temperature). This
suggests the existence of a first order phase transition. % The calculation of
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
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
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