6,899 research outputs found
Fermion Helicity Flip in Weak Gravitational Fields
The helicity flip of a spin- Dirac particle
interacting gravitationally with a scalar field is analyzed in the context of
linearized quantum gravity. It is shown that massive fermions may have their
helicity flipped by gravity, in opposition to massless fermions which preserve
their helicity.Comment: RevTeX 3.0, 8 pages, 3 figures (available upon request), Preprint
IFT-P.013/9
Irrigated rice area estimation using remote sensing techniques: Project's proposal and preliminary results
The development of a methodology for annual estimates of irrigated rice crop in the State of Rio Grande do Sul, Brazil, using remote sensing techniques is proposed. The project involves interpretation, digital analysis, and sampling techniques of LANDSAT imagery. Results are discussed from a preliminary phase for identifying and evaluating irrigated rice crop areas in four counties of the State, for the crop year 1982/1983. This first phase involved just visual interpretation techniques of MSS/LANDSAT images
Semiclassical approach to universality in quantum chaotic transport
The statistics of quantum transport through chaotic cavities with two leads
is encoded in transport moments , where is the
transmission matrix, which have a known universal expression for systems
without time-reversal symmetry. We present a semiclassical derivation of this
universality, based on action correlations that exist between sets of long
scattering trajectories. Our semiclassical formula for holds for all
values of and arbitrary number of open channels. This is achieved by
mapping the problem into two independent combinatorial problems, one involving
pairs of set partitions and the other involving factorizations in the symmetric
group.Comment: Published version. Changes in presentatio
Avaliação do efeito cicatrizante da quitosana por aplicação tópica em ratos.
bitstream/CNPDIA-2009-09/11045/1/DOC29_2007.pd
Executive report: Results of the IRGA-CNPq/INPE experimental project
A methodology for identifying and evaluating crop area with irrigated rice is described, using MSS-LANDSAT data. The maps of the spatial rice crop areas in the studied region are presented. The calculation of rice growing area from the LANDSAT images are included
INPE's crop survey program using combined LANDSAT and aircraft data
There are no author-identified significant results in this report
Multi Matrix Vector Coherent States
A class of vector coherent states is derived with multiple of matrices as
vectors in a Hilbert space, where the Hilbert space is taken to be the tensor
product of several other Hilbert spaces. As examples vector coherent states
with multiple of quaternions and octonions are given. The resulting generalized
oscillator algebra is briefly discussed. Further, vector coherent states for a
tensored Hamiltonian system are obtained by the same method. As particular
cases, coherent states are obtained for tensored Jaynes-Cummings type
Hamiltonians and for a two-level two-mode generalization of the Jaynes-Cummings
model.Comment: 24 page
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