161 research outputs found
Gravity model comparison using Geos-1 long arc orbital solutions
Gravity model comparison using Geos-1 long arc orbital solution
Evaluation of the Goddard range and range rate system at Rosman by intercomparison with GEOS 1 long-arc orbital solutions
Evaluation of Goddard range and range rate system at Rosman by intercomparison with GEOS 1 long-arc orbital solution
Research and development study on multimode system applications in the area of time of flight and coincidence measurements
Technical specifications for multimode digital storage device, and applications to time of flight and coincidence measurement
A -estimate for the parabolic Monge-Amp\`{e}re equation on complete non-compact K\"ahler manifolds
In this article we study the K\"ahler Ricci flow, the corresponding parabolic
Monge Amp\`{e}re equation and complete non-compact K\"ahler Ricci flat
manifolds. In our main result Theorem \ref{mainthm} we prove that if
is sufficiently close to being K\"ahler Ricci flat in a suitable sense, then
the K\"ahler Ricci flow \eqref{KRF} has a long time smooth solution
converging smoothly uniformly on compact sets to a complete K\"ahler Ricci flat
metric on . The main step is to obtain a uniform -estimates for the
corresponding parabolic Monge Amp\`{e}re equation. Our results on this can be
viewed as a parabolic version of the main results in \cite{TY3} on the elliptic
Monge Amp\`{e}re equation
A Reformulation of the Hoop Conjecture
A reformulation of the Hoop Conjecture based on the concept of trapped circle
is presented. The problems of severe compactness in every spatial direction,
and of how to superpose the hoops with the surface of the black hole, are
resolved. A new conjecture concerning "peeling" properties of
dynamical/trapping horizons is propounded. A novel geometric Hoop inequality is
put forward. The possibility of carrying over the results to arbitrary
dimension is discussed.Comment: 6 pages, no figures. New references included, typos corrected,
explanatory comments added. Much shorter version, in order to match EPL
length restrictions. To be published in EP
Improved perturbation theory in the vortex liquids state of type II superconductors
We develop an optimized perturbation theory for the Ginzburg - Landau
description of thermal fluctuations effects in the vortex liquids. Unlike the
high temperature expansion which is asymptotic, the optimized expansion is
convergent. Radius of convergence on the lowest Landau level is in
2D and in 3D. It allows a systematic calculation of magnetization
and specific heat contributions due to thermal fluctuations of vortices in
strongly type II superconductors to a very high precision. The results are in
good agreement with existing Monte Carlo simulations and experiments.
Limitations of various nonperturbative and phenomenological approaches are
noted. In particular we show that there is no exact intersection point of the
magnetization curves both in 2D and 3D.Comment: 24 pages, 9 figure
Bulk and element specific magnetism of the medium and high entropy Cantor-Wu alloys
Magnetic Compton scattering, x-ray magnetic circular dichroism spectroscopy
and bulk magnetometry measurements are performed on a set of medium (NiFeCo and
NiFeCoCr) and high (NiFeCoCrPd and NiFeCoCrMn) entropy Cantor-Wu alloys. The
bulk spin momentum densities determined by magnetic Compton scattering are
remarkably isotropic, and this is a consequence of the smearing of the
electronic structure by disorder scattering of the electron quasiparticles.
Non-zero x-ray magnetic circular dichroism signals are observed for every
element in every alloy indicating differences in the populations of the
majority and minority spin states implying finite magnetic moments. When Cr is
included in the solid solution, the Cr spin moment is unambiguously
antiparallel to the total magnetic moment, while a vanishingly small magnetic
moment is observed for Mn, despite calculations indicating a large moment. Some
significant discrepancies are observed between the experimental bulk and
surface magnetic moments. Despite the lack of quantitative agreement, the
element specific surface magnetic moments seem to be qualitatively reasonable
Search for the Decays B^0 -> D^{(*)+} D^{(*)-}
Using the CLEO-II data set we have searched for the Cabibbo-suppressed decays
B^0 -> D^{(*)+} D^{(*)-}. For the decay B^0 -> D^{*+} D^{*-}, we observe one
candidate signal event, with an expected background of 0.022 +/- 0.011 events.
This yield corresponds to a branching fraction of Br(B^0 -> D^{*+} D^{*-}) =
(5.3^{+7.1}_{-3.7}(stat) +/- 1.0(syst)) x 10^{-4} and an upper limit of Br(B^0
-> D^{*+} D^{*-}) D^{*\pm} D^\mp and
B^0 -> D^+ D^-, no significant excess of signal above the expected background
level is seen, and we calculate the 90% CL upper limits on the branching
fractions to be Br(B^0 -> D^{*\pm} D^\mp) D^+
D^-) < 1.2 x 10^{-3}.Comment: 12 page postscript file also available through
http://w4.lns.cornell.edu/public/CLNS, submitted to Physical Review Letter
Successful Completion of the Top-off Upgrade of the Advanced Light Source
An upgrade of the Advanced Light Source to enable top-off operation has been completed during the last four years. The final work centered around radiation safety aspects, culminating in a systematic proof that top-off operation is equally safe as decaying beam operation. Commissioning and transition to full user operations happened in late 2008 and early 2009. Top-off operation at the ALS provides a very large increase in time-averaged brightness (by about a factor of 10) as well as improvements in beam stability. The following sections provide an overview of the radiation safety rationale, commissioning results, as well as experience in user operations
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