2,317 research outputs found
Reply to "Comment on 'Gravitating Magnetic Monopole in the Global Monopole Spacetime' "
In this Reply I present some arguments in favor of the stability of the
topological defect composed by global and magnetic monopoles.Comment: 1 page, no figures. Revised version improves the theoretical analysis
about electrostatic self-interaction in the global monopole spacetim
Electrostatic in Reissner-Nordstrom space-time with a conical defect
We calculate the electrostatic potential generated by a point charge in the
space-time of Reissner-Nordstrom with a conical defect. An expression for the
self-energy is also presented.Comment: 7 pages, LATEX fil
Vacuum Polarization for a Massless Spin-1/2 Field in the Global Monopole Spacetime at Nonzero Temperature
In this paper we present the effects produced by the temperature in the
renormalized vacuum expectation value of the zero-zero component of the
energy-momentum tensor associated with massless left-handed spinor field in the
pointlike global monopole spacetime. In order to develop this calculation we
had to obtain the Euclidean thermal Green function in this background. Because
the expression obtained for the thermal energy density cannot be expressed in a
closed form, its explicit dependence on the temperature is not completely
evident. So, in order to obtain concrete information about its thermal
behavior, we develop a numerical analysis of our result in the high-temperature
limit for specific values of the parameter which codify the presence
of the monopole.Comment: 22 pages, LaTex format, 5 figure
Self-similar magnetoresistance of Fibonacci ultrathin magnetic films
We study numerically the magnetic properties (magnetization and
magnetoresistance) of ultra-thin magnetic films (Fe/Cr) grown following the
Fibonacci sequence. We use a phenomenological model which includes Zeeman,
cubic anisotropy, bilinear and biquadratic exchange energies. Our physical
parameters are based on experimental data recently reported, which contain
biquadratic exchange coupling with magnitude comparable to the bilinear
exchange coupling. When biquadratic exchange coupling is sufficiently large a
striking self-similar pattern emerges.Comment: 5 pages, 5 EPS figures, REVTeX, accepted for publication in Phys.
Rev.
Vacuum Polarization in the Spacetime of a Scalar-Tensor Cosmic String
We study the vacuum polarization effect in the spacetime generated by a
magnetic flux cosmic string in the framework of a scalar-tensor gravity. The
vacuum expectation values of the energy-momentum tensor of a conformally
coupled scalar field are calculated. The dilaton's contribution to the vacuum
polarization effect is shown explicitly.Comment: 11 pages, LATEX file, 2 eps figure
Review of a Small-scale Pelagic Longline Fishery off Northeastern Brazil
The annual catches of four small longliners operating off northeast Brazil from 1983 to 1997 were examined across different areas and locations. The total catch comprised tunas (30%), sharks (54%), billfishes (12%), and other fish species (4%). Fishing strategy and annual composition of catches showed large spatial and temporal variabilities with the dominant catches alternating among yellowfin tuna,
Thunnus albacares; gray sharks, Carcharhinus spp.; and blue shark, Prionace glauca. Catches of blue and gray sharks
showed a significant interaction among seamounts, with gray sharks occurring in maximum abundance around those seamounts
that had relatively deep summits and low-sloping depth profiles. Results are discussed in terms of the various factors that may have influenced distribution of effort
Taxa fotossintĂ©tica, produção e teor de sĂłlidos solĂșveis totais de frutos de meloeiro afetados por amarelĂŁo e por mosca-branca.
bitstream/CNPAT-2010/11913/1/bd-20.pd
Aspectos da produção de dois hĂbridos de melĂŁo em função de diferentes fontes de nitrogĂȘnio.
O objetivo deste trabalho foi de avaliar a produção dos hĂbridos
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