5,138 research outputs found
Asymptotic stability at infinity for differentiable vector fields of the plane
Let X:R2\Dr->R2 be a differentiable (but not necessarily C1) vector field,
where r>0 and Dr={z\in R2:|z|\le r}. If for some e>0 and for all p\in R2\Dr, no
eigenvalue of D_p X belongs to (-e,0]\cup {z\in\C:\mathcal{R}(z)\ge 0}, then
(a)For all p\in R2\Dr, there is a unique positive semi--trajectory of X
starting at p; (b)\mathcal{I}(X), the index of X at infinity, is a well defined
number of the extended real line [-\infty,\infty); (c) There exists a constant
vector v\in R2 such that if \mathcal{I}(X) is less than zero (resp. greater or
equal to zero), then the point at infinity \infty of the Riemann sphere
R2\cup\set{\infty} is a repellor (resp. an attractor) of the vector field X+v.Comment: 16 pages, 7 figure
Li-Yorke Chaos for Composition Operators on -Spaces
Li-Yorke chaos is a popular and well-studied notion of chaos. Several simple
and useful characterizations of this notion of chaos in the setting of linear
dynamics were obtained recently. In this note we show that even simpler and
more useful characterizations of Li-Yorke chaos can be given in the special
setting of composition operators on spaces. As a consequence we obtain a
simple characterization of weighted shifts which are Li-Yorke chaotic. We give
numerous examples to show that our results are sharp
Affine interval exchange transformations with flips and wandering intervals
There exist uniquely ergodic affine interval exchange transformations of
[0,1] with flips having wandering intervals and such that the support of the
invariant measure is a Cantor set.Comment: 7 page
Estudo comparativo entre uma pastagem nativa e o capim pangola (Digitaria decumbens) visando a produção de leite.
Produção de leite através de um criatorio em regime de campo na zona da mata de Pernambuco.Resumo
Digestibilidade da matéria seca do feno de alfafa e farelo de mamona desintoxicada pela técnica do "saco de nylon".
Comparação da digestibilidade de matéria seca do feno de alfafa e do farelo de mamona desintoxicada, pela técnica do saco de nylon, utilizando-se como repetições 2 bovinos fistulados adultos da raça holandesa
Estudos sobre nível proteíco e uréia na alimentação de vacas mestiças em produção.
Estudos sobre nivel proteina e ureia na alimentacao de vacas mesticas em producao
Self-interacting dark matter and Higgs bosons in the SU(3)_C x SU(3)_L x U(1)_N model with right-handed neutrinos
We investigate the possibility that dark matter could be made from CP-even
and CP- odd Higgs bosons in the SU(3)_C X SU(3)_L X U(1)_N (3-3-1) model with
right-handed neutrinos. This self-interacting dark matters are stable without
imposing of new symmetry and should be weak-interacting.Comment: 7 pages, Latex, To appear in Europhys. Let
Parâmetros genéticos para características de crescimento, reprodutivas e de carcaça em bovinos Canchim.
Orientador Mauricio Mello de Alenca
Comment on ``Majoron emitting neutrinoless double beta decay in the electroweak chiral gauge extensions''
We point out that if the majoron-like scheme is implemented within a 331
model, there must exist at least three different mass scales for the scalar
vacuum expectation values in the model.Comment: 4 pages, no figures, Revtex. To be published in Physical Review
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