5,945 research outputs found
Galactic Collapse of Scalar Field Dark Matter
We present a scenario for galaxy formation based on the hypothesis of scalar
field dark matter. We interpret galaxy formation through the collapse of a
scalar field fluctuation. We find that a cosh potential for the
self-interaction of the scalar field provides a reasonable scenario for
galactic formation, which is in agreement with cosmological observations and
phenomenological studies in galaxies.Comment: 4 pages, 3 figue
Generalized Chaplygin Gas, Accelerated Expansion and Dark Energy-Matter Unification
We consider the scenario emerging from the dynamics of a generalized
-brane in a spacetime. The equation of state describing this
system is given in terms of the energy density, , and pressure, , by
the relationship , where is a positive constant and
. We discuss the conditions under which homogeneity arises
and show that this equation of state describes the evolution of a universe
evolving from a phase dominated by non-relativistic matter to a phase dominated
by a cosmological constant via an intermediate period where the effective
equation of state is given by .Comment: 5 pages, 4 figures, revte
Back reaction of a long range force on a Friedmann-Robertson-Walker background
It is possible that there may exist long-range forces in addition to gravity.
In this paper we construct a simple model for such a force based on exchange of
a massless scalar field and analyze its effect on the evolution of a
homogeneous Friedmann-Robertson-Walker cosmology. The presence of such an
interaction leads to an equation of state characterized by positive pressure
and to resonant particle production similar to that observed in preheating
scenarios.Comment: 14 pages, 6 color Postscript figures, LaTe
hCG administration in Saanem goats inseminated following synchronized estrus.
Proceedings of the 28th Annual Meeting of The Brazilian Embryo Technology Society - SBTE, Natal, RN, Brasil, ago. 2014
Diversidade florística em quintais agroflorestais de agroecossistemas familiares da comunidade Nova Canaã, Rio Preto da Eva-AM.
Este trabalho teve por objetivo verificar a diversidade de espécies cultivadas em pomares caseiros de agroecossistemas, onde trabalhavam agricultores familiares da comunidade Vila Canaã
Ocorrência de nematóides, fungos micorrízicos arbusculares e bactérias diazotróficas em cultivares de bananeira na chapada do Apodi, estado do Ceará.
Levantamento de espécies frutíferas em área de várzea do Município de Parintins - Amazonas.
Este trabalho buscou identificar as espécies frutíferas que são encontradas nos quintais florestais em áreas de várzeas e descrever a sua importância e a sua utilização pelos ribeirinhos e agricultores do município de Parintins ? AM
Avaliação econômica de alta prevalência de infecção urinária em matrizes em um sistema intensivo de produçao de suínos.
bitstream/CNPSA/11287/1/cot259.pd
Avaliação de clones de mandioca visando o processamento industrial em Dourados, MS.
Publicado também na: RAT: Revista Raízes e Amidos Tropicais, v. 3, 2007. (SEP 036)
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