21,194 research outputs found
On the exact solutions of the Bianchi IX cosmological model in the proper time
It has recently been argued that there might exist a four-parameter analytic
solution to the Bianchi IX cosmological model, which would extend the
three-parameter solution of Belinskii et al. to one more arbitrary constant. We
perform the perturbative Painlev\'e test in the proper time variable, and
confirm the possible existence of such an extension.Comment: 8 pages, no figure, standard Latex, to appear in Regular and chaotic
dynamics (1998
General solution for Hamiltonians with extended cubic and quartic potentials
We integrate with hyperelliptic functions a two-particle Hamiltonian with
quartic potential and additionnal linear and nonpolynomial terms in the
Liouville integrable cases 1:6:1 and 1:6:8.Comment: LaTex 2e. To appear, Theoretical and Mathematical Physics 200
Relativistic Stern-Gerlach Interaction in an RF Cavity
The general expression of the Stern-Gerlach force is deduced for a
relativistic spin-1/2 particle which travels inside a time varying magnetic
field. This result was obtained either by means of two Lorentz boosts or
starting from Dirac's equation. Then, the utilization of this interaction for
attaining the spin states separation is reconsidered in a new example using a
new radio-frequency arrangement.Comment: 12 pages, 4 figure
Meridional heat transport at the onset of winter stratospheric warming
A continuous vertical flow of energy toward high altitude was verified. This process produced a dynamic instability of the stratospheric polar vortex. A meridional heat transport ws primed toward the north, which generated a warming trend
GreenPhylDB v2.0: An improved database for plant functional genomics
Poster presented at 2009 Annual Research Meeting of the Generation Challenge Programme. Bamako (Mali), 20-23 September 200
Sub-10 nm colloidal lithography for integrated spin-photo-electronic devices
Colloidal lithography [1] is how patterns are reproduced in a variety of
natural systems and is used more and more as an efficient fabrication tool in
bio-, opto-, and nano-technology. Nanoparticles in the colloid are made to form
a mask on a given material surface, which can then be transferred via etching
into nano-structures of various sizes, shapes, and patterns [2,3]. Such
nanostructures can be used in biology for detecting proteins [4] and DNA [5,6],
for producing artificial crystals in photonics [7,8] and GHz oscillators in
spin-electronics [9-14]. Scaling of colloidal patterning down to 10-nm and
below, dimensions comparable or smaller than the main relaxation lengths in the
relevant materials, including metals, is expected to enable a variety of new
ballistic transport and photonic devices, such as spin-flip THz lasers [15]. In
this work we extend the practice of colloidal lithography to producing
large-area, near-ballistic-injection, sub-10 nm point-contact arrays and
demonstrate their integration in to spin-photo-electronic devices.Comment: 15 pages, 5 figure
Intrabeam Scattering In The CERN Anti-proton Accumulator
The existing theories of intrabeam scattering, valid for high-energy rings ( gamma or=10), are improved and modified to give results applicable to the CERN Antiproton Accumulator (AA), which operates at lower energies ( gamma approximately=3.77). A comparison is made between theoretical evaluations and measured data, gathered by loading AA with high-intensity proton beams. The agreement obtained is rather satisfactory and this represents the first experimental check of the most up to date intrabeam-scattering theories
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