150,996 research outputs found
Some identities on derangement and degenerate derangement polynomials
In combinatorics, a derangement is a permutation that has no fixed points.
The number of derangements of an n-element set is called the n-th derangement
number. In this paper, as natural companions to derangement numbers and
degenerate versions of the companions we introduce derangement polynomials and
degenerate derangement polynomials. We give some of their properties,
recurrence relations and identities for those polynomials which are related to
some special numbers and polynomials.Comment: 12 page
New identities involving q-Euler polynomials of higher order
In this paper we give new identities involving q-Euler polynomials of higher
order.Comment: 11 page
Modulation of the Curie Temperature in Ferromagnetic/Ferroelectric Hybrid Double Quantum Wells
We propose a ferromagnetic/ferroelectric hybrid double quantum well
structure, and present an investigation of the Curie temperature (Tc)
modulation in this quantum structure. The combined effects of applied electric
fields and spontaneous electric polarization are considered for a system that
consists of a Mn \delta-doped well, a barrier, and a p-type ferroelectric well.
We calculate the change in the envelope functions of carriers at the lowest
energy sub-band, resulting from applied electric fields and switching the
dipole polarization. By reversing the depolarizing field, we can achieve two
different ferromagnetic transition temperatures of the ferromagnetic quantum
well in a fixed applied electric field. The Curie temperature strongly depends
on the position of the Mn \delta-doped layer and the polarization strength of
the ferroelectric well.Comment: 9 pages, 5 figures, to be published in Phys. Rev. B (2006) minor
revision: One of the line types is changed in Fig.
Extended Optical Model Analyses of Elastic Scattering and Fusion Cross Section Data for the 7Li+208Pb System at Near-Coulomb-Barrier Energies using the Folding Potential
Simultaneous analyses previously made for elastic scattering and
fusion cross section data for the Li+Pb system is extended to the
Li+Pb system at near-Coulomb-barrier energies based on the
extended optical model approach, in which the polarization potential is
decomposed into direct reaction (DR) and fusion parts. Use is made of the
double folding potential as a bare potential. It is found that the experimental
elastic scattering and fusion data are well reproduced without introducing any
normalization factor for the double folding potential and that both the DR and
fusion parts of the polarization potential determined from the
analyses satisfy separately the dispersion relation. Further, we find that the
real part of the fusion portion of the polarization potential is attractive
while that of the DR part is repulsive except at energies far below the Coulomb
barrier energy. A comparison is made of the present results with those obtained
from the Continuum Discretized Coupled Channel (CDCC) calculations and a
previous study based on the conventional optical model with a double folding
potential. We also compare the present results for the Li+Pb system
with the analysis previously made for the Li+Pb system.Comment: 7 figures, submitted to PR
Entropy of the Randall-Sundrum brane world with the generalized uncertainty principle
By introducing the generalized uncertainty principle, we calculate the
entropy of the bulk scalar field on the Randall-Sundrum brane background
without any cutoff. We obtain the entropy of the massive scalar field
proportional to the horizon area. Here, we observe that the mass contribution
to the entropy exists in contrast to all previous results, which is independent
of the mass of the scalar field, of the usual black hole cases with the
generalized uncertainty principle.Comment: 12 pages. The improved version published in Phys. Rev.
Extended Optical Model Analyses of Elastic Scattering and Fusion Cross Section Data for the C+Pb System at Near-Coulomb-Barrier Energies by using a Folding Potential
Simultaneous analyses are performed for elastic scattering and
fusion cross section data for the C+Pb system at
near-Coulomb-barrier energies by using the extended optical model approach in
which the polarization potential is decomposed into direct reaction (DR) and
fusion parts. Use is made of the double folding potential as a bare potential.
It is found that the experimental elastic scattering and fusion data are well
reproduced without introducing any normalization factor for the double folding
potential and also that both DR and fusion parts of the polarization potential
determined from the analyses satisfy separately the dispersion
relation. Furthermore, it is shown that the imaginary parts of both DR and
fusion potentials at the strong absorption radius change very rapidly, which
results in a typical threshold anomaly in the total imaginary potential as
observed with tightly bound projectiles such as -particle and O.Comment: 26 pages, 7 figures, submitted to Physical Review
Multivariate p-dic L-function
We construct multivariate p-adic L-function in the p-adic number fild by
using Washington method.Comment: 9 page
Cold dust clumps in dynamically hot gas
Aims. We present clumps of dust emission from Herschel observations of the Large Magellanic Cloud (LMC) and their physical and statistical
properties. We catalog cloud features seen in the dust emission from Herschel observations of the LMC, the Magellanic type irregular galaxy
closest to the Milky Way, and compare these features with Hi catalogs from the ATCA+Parkes Hi survey.
Methods. Using an automated cloud-finding algorithm, we identify clouds and clumps of dust emission and examine the cumulative mass distribution
of the detected dust clouds. The mass of cold dust is determined from physical parameters that we derive by performing spectral energy distribution
fits to 250, 350, and 500 μm emission from SPIRE observations using dust grain size distributions for graphite/silicate in low-metallicity
extragalactic environments.
Results. The dust cloud mass spectrum follows a power law distribution with an exponent of γ = −1.8 for clumps larger than 4 × 10^2 M_⊙ and is
similar to the Hi mass distribution. This is expected from the theory of ISM structure in the vicinity of star formation
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