4,919 research outputs found
Public Interest Immunity: Al Megrahi v HM Advocate
The Lockerbie case has already contributed significantly to the jurisprudence of the law of evidence. Al Megrahi v HM Advocate continues in that vein, shedding some light on how the law relating to public interest immunity now operates following devolution
Fermi-Dirac statistics and the number theory
We relate the Fermi-Dirac statistics of an ideal Fermi gas in a harmonic trap
to partitions of given integers into distinct parts, studied in number theory.
Using methods of quantum statistical physics we derive analytic expressions for
cumulants of the probability distribution of the number of different
partitions.Comment: 7pages, 2 figures, epl.cls, revised versio
An attempt to observe economy globalization: the cross correlation distance evolution of the top 19 GDP's
Economy correlations between the 19 richest countries are investigated
through their Gross Domestic Product increments. A distance is defined between
increment correlation matrix elements and their evolution studied as a function
of time and time window size. Unidirectional and Bidirectional Minimal Length
Paths are generated and analyzed for different time windows. A sort of critical
correlation time window is found indicating a transition for best observations.
The mean length path decreases with time, indicating stronger correlations. A
new method for estimating a realistic minimal time window to observe
correlations and deduce macroeconomy conclusions from such features is thus
suggested.Comment: to be published in the Dyses05 proceedings, in Int. J. Mod Phys C 15
pages, 5 figures, 1 tabl
Evanescence in Coined Quantum Walks
In this paper we complete the analysis begun by two of the authors in a
previous work on the discrete quantum walk on the line [J. Phys. A 36:8775-8795
(2003) quant-ph/0303105 ]. We obtain uniformly convergent asymptotics for the
"exponential decay'' regions at the leading edges of the main peaks in the
Schr{\"o}dinger (or wave-mechanics) picture. This calculation required us to
generalise the method of stationary phase and we describe this extension in
some detail, including self-contained proofs of all the technical lemmas
required. We also rigorously establish the exact Feynman equivalence between
the path-integral and wave-mechanics representations for this system using some
techniques from the theory of special functions. Taken together with the
previous work, we can now prove every theorem by both routes.Comment: 32 pages AMS LaTeX, 5 figures in .eps format. Rewritten in response
to referee comments, including some additional references. v3: typos fixed in
equations (131), (133) and (134). v5: published versio
Casimir force between designed materials: what is possible and what not
We establish strict upper limits for the Casimir interaction between
multilayered structures of arbitrary dielectric or diamagnetic materials. We
discuss the appearance of different power laws due to frequency-dependent
material constants. Simple analytical expressions are in good agreement with
numerical calculations based on Lifshitz theory. We discuss the improvements
required for current (meta) materials to achieve a repulsive Casimir force.Comment: 9 pages, 4 figures, graphicx, v4: Europhysics Letters, in pres
A zeta function approach to the relation between the numbers of symmetry planes and axes of a polytope
A derivation of the Ces\`aro-Fedorov relation from the Selberg trace formula
on an orbifolded 2-sphere is elaborated and extended to higher dimensions using
the known heat-kernel coefficients for manifolds with piecewise-linear
boundaries. Several results are obtained that relate the coefficients, ,
in the Shephard-Todd polynomial to the geometry of the fundamental domain. For
the 3-sphere we show that is given by the ratio of the volume of the
fundamental tetrahedron to its Schl\"afli reciprocal.Comment: Plain TeX, 26 pages (eqn. (86) corrected
Distinguishing cancerous from non-cancerous cells through analysis of electrical noise
Since 1984, electric cell-substrate impedance sensing (ECIS) has been used to
monitor cell behavior in tissue culture and has proven sensitive to cell
morphological changes and cell motility. We have taken ECIS measurements on
several cultures of non-cancerous (HOSE) and cancerous (SKOV) human ovarian
surface epithelial cells. By analyzing the noise in real and imaginary
electrical impedance, we demonstrate that it is possible to distinguish the two
cell types purely from signatures of their electrical noise. Our measures
include power-spectral exponents, Hurst and detrended fluctuation analysis, and
estimates of correlation time; principal-component analysis combines all the
measures. The noise from both cancerous and non-cancerous cultures shows
correlations on many time scales, but these correlations are stronger for the
non-cancerous cells.Comment: 8 pages, 4 figures; submitted to PR
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