15,710 research outputs found
Teleparallel Spin Connection
A new expression for the spin connection of teleparallel gravity is proposed,
given by minus the contorsion tensor plus a zero connection. The corresponding
minimal coupling is covariant under local Lorentz transformation, and
equivalent to the minimal coupling prescription of general relativity. With
this coupling prescription, therefore, teleparallel gravity turns out to be
fully equivalent to general relativity, even in the presence of spinor fields.Comment: 2 pages, RevTeX, to appear in Phys. Rev D (Brief Report
Fluctuation of the Initial Conditions and Its Consequences on Some Observables
We show effects of the event-by-event fluctuation of the initial conditions
(IC) in hydrodynamic description of high-energy nuclear collisions on some
observables. Such IC produce not only fluctuations in observables but, due to
their bumpy structure, several non-trivial effects appear. They enhance
production of isotropically distributed high-pT particles, making v2 smaller
there. Also, they reduce v2 in the forward and backward regions where the
global matter density is smaller, so where such effects become more
efficacious. They may also produce the so-called ridge effect in the two
large-pT particle correlation.Comment: 6 pages, 6 figures, presented at the IV Workshop on Particle
Correlations and Femtoscopy (WPCF2008), Krakow, Poland, 11-14 Sep 200
Gravitation and Duality Symmetry
By generalizing the Hodge dual operator to the case of soldered bundles, and
working in the context of the teleparallel equivalent of general relativity, an
analysis of the duality symmetry in gravitation is performed. Although the
basic conclusion is that, at least in the general case, gravitation is not dual
symmetric, there is a particular theory in which this symmetry shows up. It is
a self dual (or anti-self dual) teleparallel gravity in which, due to the fact
that it does not contribute to the interaction of fermions with gravitation,
the purely tensor part of torsion is assumed to vanish. The ensuing fermionic
gravitational interaction is found to be chiral. Since duality is intimately
related to renormalizability, this theory may eventually be more amenable to
renormalization than teleparallel gravity or general relativity.Comment: 7 pages, no figures. Version 2: minor presentation changes,
references added. Accepted for publication in Int. J. Mod. Phys.
Níveis de danos do nematóide de cisto da soja.
bitstream/item/24729/1/COT200269.pdfDocumento on-line
Disseminação pelo vento do nematóide de cisto da soja (Heterodera glycines).
bitstream/item/39430/1/cot16-96.pd
Reprodução de Meloidogyne javanica em algumas plantas daninhas de ocorrência freqüente na Regiao Oeste do Brasil.
bitstream/item/39434/1/Cot19-97.pd
Reprodução do nematoide de galhas em plantas forrageiras utilizadas em sistemas integrados de produção agropecuária.
bitstream/item/39450/1/Cot28-98.pd
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