10,600 research outputs found
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
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.
Algebraic integrability of confluent Neumann system
No full textIn this paper we study the Neumann system, which describes the harmonic
oscillator (of arbitrary dimension) constrained to the sphere. In particular
we will consider the confluent case where two eigenvalues of the potential
coincide, which implies that the system has symmetry. We will prove
complete algebraic integrability of the confluent Neumann system and show
that its flow can be linearized on the generalized Jacobian torus of some singular
algebraic curve. The symplectic reduction of S 1 action will be described and
we will show that the general Rosochatius system is a symplectic quotient of
the confluent Neumann system, where all the eigenvalues of the potential are
double
Convergence of infinite products of matrices and inner-outer iteration schemes
No full textElsner L, Bru R, Neumann MM. Convergence of infinite products of matrices and inner-outer iteration schemes. Electronic Transactions on Numerical Analysis. 1994;2:183-193
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
Groupe V/a : Rapports sur le mémoire de M. G. L. Neumann. Rapports des Commissaires
No full textHomès-Van Schoor Germaine, Lebrun Jean, Homès Marcel Victor. Groupe V/a : Rapports sur le mémoire de M. G. L. Neumann. Rapports des Commissaires. In: Bulletin de la Classe des sciences, tome 66, 1980. pp. 837-839
Groupe V/a : Rapports sur le mémoire de M. G. L. Neumann. Rapports des Commissaires
No full textHomès-Van Schoor Germaine, Lebrun Jean, Homès Marcel Victor. Groupe V/a : Rapports sur le mémoire de M. G. L. Neumann. Rapports des Commissaires. In: Bulletin de la Classe des sciences, tome 66, 1980. pp. 837-839
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
Examples of compact quantum groups with L ∞ ( G ) a factor
No full textFor each λ∈] 0,1] we exhibit an uncountable family of compact quantum groups G such that the von Neumann algebra L∞ (G) is the injective factor of type IIIλ with separable predual. We also show that uncountably many injective factors of type III0 arise as L∞ (G) for some compact quantum group G. We introduce natural invariants of quantum groups related to the scaling group, modeled on the Connes invariant T for von Neumann algebras. We compute the values of these invariants in our examples, which allows us to distinguish between them. We also investigate their connection to the Connes invariants T(L∞(G)), S(L∞(G)). In the final section we show that for a compact quantum group G the von Neumann algebra L∞(G) cannot have a direct summand of the form B(H) with dim H=∞. In particular, factors of type I (of any dimension) cannot be obtained as L∞(G) for a non-trivial compact quantum group G
Chemical electric field effects in biological macromolecules
No full textNeumann E. Chemical electric field effects in biological macromolecules. Progress in Biophysics and Molecular Biology. 1986;47(3):197-231
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