525 research outputs found
Blow-up solutions for linear perturbations of the Yamabe equation
For a smooth, compact Riemannian manifold (M,g) of dimension N \geg 3, we
are interested in the critical equation where \Delta_g is the Laplace--Beltrami
operator, S_g is the Scalar curvature of (M,g), , and
is a small parameter
Four-body effects on 9Be + 208Pb scattering and fusion around the Coulomb barrier
We investigate the 9Be + 208Pb elastic scattering and fusion at energies
around the Coulomb barrier. The Be nucleus is described in a \alpha +
\alpha + n three-body model, using the hyperspherical coordinate method. The
scattering with Pb is then studied with the Continuum Discretized
Coupled Channel (CDCC) method, where the \alpha + \alpha + n continuum is
approximated by a discrete number of pseudostates. Optical potentials for the
Pb and Pb systems are taken from the literature. We
present elastic-scattering and fusion cross sections at different energies, and
investigate the convergence with respect to the truncation of the \alpha +
\alpha + n continuum. A good agreement with experiment is obtained, considering
that there is no parameter fitting. We show that continuum effects increase at
low energies.Comment: 6 pages, 4 figures. Submitted to the proceedings of the "NUBA
Conference Series -1: Nuclear Physics and Astrophysics" Adrasan-Antalya,
Turkey, September 15-21, 201
Nonlinear Klein-Gordon-Maxwell systems with Neumann boundary conditions on a Riemannian manifold with boundary
Let (M,g) be a smooth compact, n dimensional Riemannian manifold, n=3,4 with
smooth n-1 dimensional boundary. We search the positive solutions of the
singularly perturbed Klein Gordon Maxwell Proca system with homogeneous Neumann
boundary conditions or for the singularly perturbed Klein Gordon Maxwell system
with mixed Dirichlet Neumann homogeneous boundary conditions. We prove that
stable critical points of the mean curvature of the boundary generates
solutions when the perturbation parameter is sufficiently small.Comment: arXiv admin note: text overlap with arXiv:1410.884
Accounting for heterogeneous variances in multitrait evaluation of Jersey type traits
peer reviewedThe multitrait genetic evaluation system for type traits was modified to estimate adjustments for heterogeneous variance (HV) simultaneously with estimated breeding values (EBV) for final score and 14 linear traits. Each variance within herd, year, and parity was regressed toward a predicted variance, which was determined by fitting a model with fixed effects of the mean final score for herd, size of the contemporary group, appraisal month, and year-season and a random effect for herd-appraisal date. Herd-appraisal date was included as a random effect to regress the observed heterogeneity for a given herd-appraisal date toward the fixed effects. Method R was used to estimate variances for the heterogeneity model in each EBV iteration. To evaluate the effect of the adjustment, parent averages were calculated from evaluations with recent appraisals removed. The adjustment slightly improved correlations within birth year between those parent averages and EBV from current data on bulls for most traits, but did not improve correlations for final score, strength, dairy form, teat length, or foot angle. Annual trends for EBV were lower with HV adjustment than for unadjusted EBV for all traits except final score and rump angle for cows and rump width for bulls, which were essentially unchanged. Standard deviations of Mendelian sampling (evaluation minus mean of parent evaluations) declined less over time for HV-adjusted than for unadjusted evaluations. The slope at year 2000 of Mendelian-sampling standard deviations from HV-adjusted evaluations ranged from 10.0% for udder depth to 42.7% for teat length compared with the slope for unadjusted evaluations. This HV adjustment, which was implemented for USDA evaluations in May 2001 for Jerseys and in 2002 for other breeds, improves the accuracy of evaluations, particularly comparisons over time, by accounting for the change in variation
Sharp constants in weighted trace inequalities on Riemannian manifolds
We establish some sharp weighted trace inequalities
W^{1,2}(\rho^{1-2\sigma}, M)\hookrightarrow L^{\frac{2n}{n-2\sigma}}(\pa M)
on dimensional compact smooth manifolds with smooth boundaries, where
is a defining function of and . This is stimulated
by some recent work on fractional (conformal) Laplacians and related problems
in conformal geometry, and also motivated by a conjecture of Aubin.Comment: 34 page
A compactness theorem for scalar-flat metrics on manifolds with boundary
Let (M,g) be a compact Riemannian manifold with boundary. This paper is
concerned with the set of scalar-flat metrics which are in the conformal class
of g and have the boundary as a constant mean curvature hypersurface. We prove
that this set is compact for dimensions greater than or equal to 7 under the
generic condition that the trace-free 2nd fundamental form of the boundary is
nonzero everywhere.Comment: 49 pages. Final version, to appear in Calc. Var. Partial Differential
Equation
Quantization for an elliptic equation of order 2m with critical exponential non-linearity
On a smoothly bounded domain we consider a sequence of
positive solutions in to
the equation subject to Dirichlet
boundary conditions, where . Assuming that
we
prove that is an integer multiple of
\Lambda_1:=(2m-1)!\vol(S^{2m}), the total -curvature of the standard
-dimensional sphere.Comment: 33 page
Existence of solutions to a higher dimensional mean-field equation on manifolds
For we prove an existence result for the equation on a closed Riemannian
manifold of dimension for certain values of .Comment: 15 Page
A threshold phenomenon for embeddings of into Orlicz spaces
We consider a sequence of positive smooth critical points of the
Adams-Moser-Trudinger embedding of into Orlicz spaces. We study its
concentration-compactness behavior and show that if the sequence is not
precompact, then the liminf of the -norms of the functions is greater
than or equal to a positive geometric constant.Comment: 14 Page
New Gravity Map of the Western Galicia Margin:The Spanish Exclusive Economic Zone Project
Since 1995, the most intensive mapping of
the seafloor off the Spanish coast has been
carried out in the framework of the Spanish
Exclusive Economic Zone Project (ZEEE).The
main objectives of this project are to obtain
improved multibeam bathymetric cartography
of the areas off Spanish coastlines, and to perform
a geophysical survey,well-suited with a
10-knot navigation velocity (some techniques
requires lower navigation velocity).
The geophysical survey includes gravity, geomagnetism,
and low-penetration seismic techniques
in order to infer the geological structure
of the seafloor. Other oceanographic variables
such as current, surface salinity, and temperature
profiles, can be recorded without compromising
this systematic survey effort.
The ZEEE Project has carried out its survey
activities for one month every year.Data
acquisition is achieved aboard the Spanish
R/V Hesperides. Until 1997, surveying efforts
concentrated on the Balearic Sea and Valencia
Gulf, both in the western Mediterranean Sea.
Between 1998 and 2000, the ZEEE Project
investigations were conducted offshore the
Canary Archipelago. Since 2001, the third
phase of the program has been focused on
the West Galicia Margin in the northeastern
Atlantic Ocean.
Survey results on the West Galicia Margin area
are of interest for two key reasons. First, there
is great scientific interest in the improvement
of the knowledge of this non-volcanic rifting
margin, since this margin offers good conditions
for the study of the processes that take
place in this type of geological context,because
it is sediment-starved.
Second, the obtained results also have major
socioeconomic repercussions because they
can prove significant to defining the expansion
of the Spanish shelf,beyond Spainâs Economic
Exclusive Zone distance of 200 nautical miles.
All of the gravity data acquired to date on
this area have been stored as a database, with
the aim of preparing gravity anomaly maps
on a scale 1:200,000.The database and gravity
anomaly charts from the ZEEE Project will
provide the most coherent and complete gravity
perspective available for this area.
This article describes the efforts and accomplishments
of the project to date
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