9,158 research outputs found
On the probability distributions of the force and potential energy for a system with an infinite number of random point sources
In this work, we study the probability distribution for the force and
potential energy of a test particle interacting with point random sources
in the limit . The interaction is given by a central
potential in a -dimensional euclidean space, where
is the random relative distance between the source and the test particle,
is the force exponent, and is the coupling parameter. In order to
assure a well-defined limit for the probability distribution of the force and
potential energy, we { must} renormalize the coupling parameter and/or the
system size as a function of the number of sources.
We show the existence of three non-singular limits, depending on the exponent
and the spatial dimension . (i) For the force and
potential energy { converge} to their respective mean values. This limit is
called Mean Field Limit. (ii) For the potential energy converges
to a random variable and the force to a random vector. This limit is called
Thermodynamic Limit. (iii) For the potential energy converges to
its mean and the force to a random vector. This limit is called Mixed Limit
Also, we show the existence of two singular limits: (iv) for the
potential energy converges to its mean and the force to zero, and (v) for
the energy converges to a finite value and the force to a random
vector.Comment: 25 pages, 5 tables, Preprint Articl
Caracterização do cruzamento entre as raças suínas landrace x large White x moura pra formação de híbridos da linha fêmea.
Existence of positive solutions of a superlinear boundary value problem with indefinite weight
We deal with the existence of positive solutions for a two-point boundary
value problem associated with the nonlinear second order equation
. The weight is allowed to change its sign. We assume
that the function is
continuous, and satisfies suitable growth conditions, so as the case
, with , is covered. In particular we suppose that is
large near infinity, but we do not require that is non-negative in a
neighborhood of zero. Using a topological approach based on the Leray-Schauder
degree we obtain a result of existence of at least a positive solution that
improves previous existence theorems.Comment: 12 pages, 4 PNG figure
Even Galois Representations and the Fontaine--Mazur conjecture II
We prove, under mild hypotheses, that there are no irreducible
two-dimensional_even_ Galois representations of \Gal(\Qbar/\Q) which are de
Rham with distinct Hodge--Tate weights. This removes the "ordinary" hypothesis
required in previous work of the author. We construct examples of irreducible
two-dimensional residual representations that have no characteristic zero
geometric (= de Rham) deformations.Comment: Updated to take into account suggestions of the referee; the main
theorems remain unchange
Efeito de diferentes inseticidas no controle de Dalbulus maidis e Elasmopalpus lignosellus em milho.
On "Ergodicity and Central Limit Theorem in Systems with Long-Range Interactions" by Figueiredo et al
In the present paper we refute the criticism advanced in a recent preprint by
Figueiredo et al [1] about the possible application of the -generalized
Central Limit Theorem (CLT) to a paradigmatic long-range-interacting many-body
classical Hamiltonian system, the so-called Hamiltonian Mean Field (HMF) model.
We exhibit that, contrary to what is claimed by these authors and in accordance
with our previous results, -Gaussian-like curves are possible and real
attractors for a certain class of initial conditions, namely the one which
produces nontrivial longstanding quasi-stationary states before the arrival,
only for finite size, to the thermal equilibrium.Comment: 2 pages, 2 figures. Short version of the paper, accepted for
publication in Europhysics Letters, (2009) in pres
Brazilian embryo industry in context: pitfalls, lessons, and expectations for the future.
Proceedings of the 31st Annual Meeting of the Brazilian Embryo Technology Society (SBTE); Cabo de Santo Agostinho, PE, Brazil, August 17th to 19th, 2017. Abstract
Aspectos biológicos do parasitóide Campolus flavicincta (Ashmead) criados em lagartas de Spodoptera frugiperda (Smith).
Estudou-se em laboratorio, aspectos biologicos do parasitoide Campoletis flavicincta (Ashmead) utilizando como hospedeiro larvas de Spodoptera frugiperda (Smith). Dez casais recem-nascidos de C. flavicincta foram individualizados no interior de vidros transparentes, (9,5 cm de diametro x 22 cm de altura) cobertos com um tecido fino, com solucao acucarada enriquecida com acido ascorbico. Sob condicoes de temperatura de 25 +/_ 2oC, umidade relativa de 70 +/- 10% e fotofase de 12 horas, cada casal recebeu diariamente cerca de 50 lagartas de tres dias de idade da especie S. frugiperda. Apos cada periodo de parasitismo as larvas foram individualizadas em copos plasticos contendo dieta artificial. O ciclo biologico total do parasitoide foi de 19,3 dias, sendo de 12,1 dias o periodo de ovo-larva e 7,2 dias o periodo de pupa. O peso medio da pupas foi de 8,3mg. A longevidade dos adultos foi em media 29,3 dias para os machos e 23,3 para as femeas. O periodo de parasitismo foi de 25 dias, com uma media de 18 lagartas parasitadas por dia. Houve predominancia de machos, com uma razao sexual de 0,15
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