41,190 research outputs found
Comment on "Head-on collision of electron acoustic solitary waves in a plasma with nonextensive hot electrons"
In a recent paper "Head-on collision of electron acoustic solitary waves in a
plasma with nonextensive hot electrons" [Astrophys. Space Sci. 338, 271-278
(2012)] Eslami, Mottaghizadeh and Pakzad deal with the problem of the head-on
collisions between two weakly nonlinear electron-acoustic solitary waves.
Unfortunately, their treatment is deficient and leads to erroneous conclusions.Comment: Accepted for publication in "Astrophysics and Space Science
Small fuel cell to eliminate pressure caused by gassing in high energy density batteries Progress report, 30 Sep. - 30 Dec. 1965
Miniature fuel cells to eliminate pressure caused by gassing in sealed silver-zinc batterie
Small fuel cell to eliminate pressure caused by gassing in high energy density batteries Final report, 30 Jun. 1965 - 30 Jun. 1966
Gas pressure reduction in silver-zinc batteries by installing miniature hydrogen-oxygen fuel cel
Small fuel cell to eliminate pressure caused by gassing in high energy density batteries Progress report, 30 Dec. 1965 - 31 Mar. 1966
Miniature fuel cell as pressure regulators in silver-zinc batterie
Small fuel cell to eliminate pressure caused by gassing in high energy density batteries Progress report, 30 Jun. - 30 Sep. 1965
Miniature fuel cells as proposed solution to gassing and pressure rise problems in sealed silver-zinc batterie
Trace functions as Laplace transforms
We study trace functions on the form t\to\tr f(A+tB) where is a
real function defined on the positive half-line, and and are
matrices such that is positive definite and is positive
semi-definite. If is non-negative and operator monotone decreasing, then
such a trace function can be written as the Laplace transform of a positive
measure. The question is related to the Bessis-Moussa-Villani conjecture.
Key words: Trace functions, BMV-conjecture.Comment: Minor change of style, update of referenc
Some Calculable Contributions to Entanglement Entropy
Entanglement entropy appears as a central property of quantum systems in
broad areas of physics. However, its precise value is often sensitive to
unknown microphysics, rendering it incalculable. By considering parametric
dependence on correlation length, we extract finite, calculable contributions
to the entanglement entropy for a scalar field between the interior and
exterior of a spatial domain of arbitrary shape. The leading term is
proportional to the area of the dividing boundary; we also extract finite
subleading contributions for a field defined in the bulk interior of a
waveguide in 3+1 dimensions, including terms proportional to the waveguide's
cross-sectional geometry; its area, perimeter length, and integrated curvature.
We also consider related quantities at criticality and suggest a class of
systems for which these contributions might be measurable.Comment: 4+ pages, 1 figure. v2: Some clarifications and more references;
updated to resemble version published in PR
Do Binary Hard Disks Exhibit an Ideal Glass Transition?
We demonstrate that there is no ideal glass transition in a binary hard-disk
mixture by explicitly constructing an exponential number of jammed packings
with densities spanning the spectrum from the accepted ``amorphous'' glassy
state to the phase-separated crystal. Thus the configurational entropy cannot
be zero for an ideal amorphous glass, presumed distinct from the crystal in
numerous theoretical and numerical estimates in the literature. This objection
parallels our previous critique of the idea that there is a most-dense random
(close) packing for hard spheres [Torquato et al, Phys. Rev. Lett., 84, 2064
(2000)].Comment: Submitted for publicatio
Detecting and diagnosing faults in dynamic stochastic distributions using a rational b-splines approximation to output PDFs
Describes the process of detecting and diagnosing faults in dynamic stochastic distributions using a rational b-splines approximation to output PDFs
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