28,094 research outputs found
Three nontrivial solutions for the p-Laplacian Neumann problems with a concave nonlinearity near the origin
No full textWe consider a nonlinear Neumann problem driven by the p-
Laplacian, with a right-hand side nonlinearity which is concave near the
origin. Using variational techniques, combined with the method of upper-lower
solutions and with Morse theory, we show that the problem has at least three
nontrivial smooth solutions, two of which have a constant sign (one positive
and one negative).FCTPOCI/MAT/55524/200
Robert Neumann: Mit eigener Feder
No full textRobert Neumann (1897–1957, Austrian exiled author and Vicepresidet of the PEN International, was even a disputatious antifascist political writer. His essays, his letters and biograpical documents give a vivid portrait of the diversity of literary life in Germay and Austria (before 1933/after 1958) and of exile in England (1933–1958).Der österreichische Schriftsteller Robert Neumann (1897–1975), Exilant und Vizepräsident des PEN International, war auch ein streitbarer antifaschistischer Publizist. Seine politisch-literarischen Aufsätze, seine Briefe und biographischen Dokumente ergeben ein lebendiges und facettenreiches Bild des literarischen Lebens in Deutschland und Österreich (vor 1933/nach 1958) und des Exils in England (1933–1958)
Equilibrio competitivo y soportes del crecimiento en el modelo de Von Neumann
No full textThis paper shows the existence of a reproducible competitive equilibrium in the general Von Neumann growth model, extending in this way a result due to Roemer.
Kochen-Specker theorem for von Neumann algebras
No full textThe Kochen-Specker theorem has been discussed intensely ever since its original proof in 1967. It is one of the central no-go theorems of quantum theory, showing the non-existence of a certain kind of hidden states models. In this paper, we first offer a new, non-combinatorial proof for quantum systems with a type I_n factor as algebra of observables, including I_infinity. Afterwards, we give a proof of the Kochen-Specker theorem for an arbitrary von Neumann algebra R without summands of types I_1 and I_2, using a known result on two-valued measures on the projection lattice P(R). Some connections with presheaf formulations as proposed by Isham and Butterfield are made
Álgebras de von Neumann - fatores
No full textDissertação (mestrado) - Universidade Federal de Santa Catarina, Centro de Ciências Físicas e Matemáticas, Programa de Pós-Graduação em Matemática e Computação Científica, Florianópolis, 2011Dada uma álgebra de von Neumann M em L(H), onde L(H) é o espaço dos operadores lineares e limitados sobre um espaço de Hilbert H, dizemos que M é um fator se seu centro consiste somente por múltiplos escalares do operador identidade de L(H). Quando M é um fator, podemos classificá-lo em tipo I, II e III. Além disso, o tipo II pode ser dividido em dois sub-tipos. O objetivo dessa dissertação é exibir exemplos de fatores, bem como exemplos dos tipos I, II e seus sub-tipos
Two Positive Solutions for a Nonlinear Neumann Problem Involving the Discrete p-Laplacian
No full textThis paper is devoted to study of existence of at least two positive solutions for a nonlinear Neumann boundary value problem involving the discrete p-Laplacian
The von Neumann Model and the Early Models of General Equilibrium
No full textThe paper reconstructs the von Neumann model, comments on its salient features and critically reviews some of its generalisations. The issues related to thetreatment of consumption, decomposability and uniqueness of the rate of growth and interest will be especially scrutinised. The most prominent models of general equilibrium that appeared before or roughly at the same time as von Neumann's model will be also reviewed in the paper and compared with it. It will be demonstrated that none of them had any noticeable influence on von Neumann's model, which is genuinely distinct, ideologically free and methodologically fresh and forward-looking. It will be argued that the model can be viewed as a brilliant mathematical metaphor of some deep-rooted old vision, pertaining to the core issues of commodity production
Neumann problem on the semi-line for the Burgers equation
No full textIn this article, the Neumann problem on the semi-line for the Burgers equation is considered. The problem is reduced to a nonlinear integral equation in one independent variable, whose unique solution is proven to exist for small time. An explicit solution is discussed as well
Multiple boundary peak solutions for some singularly perturbed Neumann problems
No full textWe consider the problem \left \{
\begin{array}{rcl} \varepsilon^2 \Delta u - u + f(u) = 0 & \mbox{ in }& \ \Omega\\ u > 0 \ \mbox{ in} \ \Omega, \ \frac{\partial u}{\partial \nu} = 0 & \mbox{ on }& \ \partial\Omega,
\end{array} \right. where \Omega is a bounded smooth domain in R^N, \varepsilon>KK-peakH(P)K-peak$ solutions.
We first use the Liapunov-Schmidt method to reduce the problem to finite dimensions.
Then we use a maximizing procedure to obtain multiple boundary spikes
On The Two Dimensional Gierer-Meinhardt system with strong coupling
No full textWe construct
solutions with
a single interior condensation point
for the
two-dimensional
Gierer-Meinhardt
system with strong coupling.
The condensation point is
located at a nondegenerate critical point of the diagonal part of the
regular part of the Green's function for -\Delta +1 nder the Neumann
boundary condition.
Our method is based on Liapunov-Schmidt reduction for a system of elliptic equations
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