47,567 research outputs found
Gravitational waves in the generalized Chaplygin gas model
The consequences of taking the generalized Chaplygin gas as the dark energy
constituent of the Universe on the gravitational waves are studied and the
spectrum obtained from this model, for the flat case, is analyzed. Besides its
importance for the study of the primordial Universe, the gravitational waves
represent an additional perspective (besides the CMB temperature and
polarization anisotropies) to evaluate the consistence of the different dark
energy models and establish better constraints to their parameters. The
analysis presented here takes this fact into consideration to open one more
perspective of verification of the generalized Chapligin gas model
applicability. Nine particular cases are compared: one where no dark energy is
present; two that simulate the -CDM model; two where the gas acts like
the traditional Chaplygin gas; and four where the dark energy is the
generalized Chaplygin gas. The different spectra permit to distinguish the
-CDM and the Chaplygin gas scenarios.Comment: Latex file, 9 pages, 11 figures eps forma
Efeito da consorciação leguminosa perene com milho sobre a infestação de carunchos e traças do milho.
Biomassa, decomposição e liberação de nutrientes por coberturas vegetais do solo em sistema orgânico de bananeira.
Os sistemas orgânicos de produção vegetal devem priorizar a reciclagem de matéria orgânica como base para a manutenção da fertilidade do solo e a nutrição das plantas. A utilização de coquetéis vegetais envolvendo leguminosas e gramíneas favorece a produção de biomassa com relação C/N intermediária àquelas obtidas em cultivos solteiros, proporcionando maior persistência das palhadas e sincronismo entre fornecimento e demanda de nutrientes para a bananeira
Stoichiometry, structure, and transport in the quasi-one-dimensional metal, Li(0.9)Mo(6)O(17)
A correlation between lattice parameters, oxygen composition, and the
thermoelectric and Hall coefficients is presented for single-crystal
Li(0.9)Mo(6)O(17), a quasi-one-dimensional (Q1D) metallic compound. The
possibility that this compound is a compensated metal is discussed in light of
a substantial variability observed in the literature for these transport
coefficients.Comment: 5 pages, 4 Figures; Phys. Rev. B (in press
Social Dilemmas and Cooperation in Complex Networks
In this paper we extend the investigation of cooperation in some classical
evolutionary games on populations were the network of interactions among
individuals is of the scale-free type. We show that the update rule, the payoff
computation and, to some extent the timing of the operations, have a marked
influence on the transient dynamics and on the amount of cooperation that can
be established at equilibrium. We also study the dynamical behavior of the
populations and their evolutionary stability.Comment: 12 pages, 7 figures. to appea
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