125,477 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
Der Gar zu gemein werdende Alte und Neue Betrug, Unter denen Reichsthalern
No full textNicht identisch mit VD18 80315232, dort: Erscheinungsvermerk "Hamburg/ druckts Conrad Neumann/ E. E. RahtsBuchdr.1704." und auf S. 148 abweichender Zeilenfall ab Z. 1 mit nur 6 Zeilen Errata; nicht identisch mit VD18 90467183, dort: "Hamburg/ Gedr. bey Conrad Neum. E. E. Hochw. RahtsBuchdr. 1704."Vorlageform des Erscheinungsvermerks: In Verlegung des Autoris und bey demselben zubekommen. Hamburg, druckts Conrad Neumann, E. E. Hochw. RahtsBuchdr. 1704.Ill., Titelvignette (Kupferst.
Der Gar zu gemein werdende Alte und Neue Betrug, Unter denen Reichsthalern
No full textNicht identisch mit VD18 80315232, dort: Erscheinungsvermerk "Hamburg/ druckts Conrad Neumann/ E. E. RahtsBuchdr.1704." und auf S. 148 abweichender Zeilenfall ab Z. 1 mit nur 6 Zeilen Errata; nicht identisch mit VD18 90467205, dort: "Hamburg/ druckts Conrad Neumann/ E. E. RahtsBuchdr.1704."Vorlageform des Erscheinungsvermerks: In Verlegung des Autoris und bey demselben zubekommen. Hamburg, Gedr. bey Conrad Neum. E. E. Hochw. RahtsBuchdr. 1704.Ill., Titelvignette (Kupferst.
Trees, norms on H(1), and the Bieri-Neumann-Strebel invariant.
No full textTrees, norms on H(1), and the Bieri-Neumann-Strebel invariant
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
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
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
Das Echo oder Anekdoten, Erzählungen und charakteristische Züge aus der Vorzeit und Gegenwart / Herausgegeben von Sebaldo, Verfasser von Leipzigs Vorzeit [i.e. Johann Carl August Neumann] ; H. 1
No full textDAS ECHO ODER ANEKDOTEN, ERZÄHLUNGEN UND CHARAKTERISTISCHE ZÜGE AUS DER VORZEIT UND GEGENWART / HERAUSGEGEBEN VON SEBALDO, VERFASSER VON LEIPZIGS VORZEIT [I.E. JOHANN CARL AUGUST NEUMANN] ; H. 1
Das Echo oder Anekdoten, Erzählungen und charakteristische Züge aus der Vorzeit und Gegenwart / Herausgegeben von Sebaldo, Verfasser von Leipzigs Vorzeit [i.e. Johann Carl August Neumann] (-)
Das Echo oder Anekdoten, Erzählungen und charakteristische Züge aus der Vorzeit und Gegenwart / Herausgegeben von Sebaldo, Verfasser von Leipzigs Vorzeit [i.e. Johann Carl August Neumann] ; H. 1 (H. 1) (1)
Cover (1)
Titelseite (3)
Vorwort. (5)
Inhalt. (7)
Altdeutsceh Rechtlichkeit. - Magister Sebastian Fröschel. (9)
Schicksal eines alten Geistlichen. - Christliche Erinnerung. (63
Introducing Formalism in Economics: The Growth Model of John von Neumann
No full textThe objective is to interpret John von Neumann's growth model as a decisive step of the forthcoming formalist revolution of the 1950s in economics. This model gave rise to an impressive variety of comments about its classical or neoclassical underpinnings. We go beyond this traditional criterion and interpret rather this model as the manifestation of von Neumann's involvement in the formalist programme of mathematician David Hilbert. We discuss the impact of Kurt Gödel’s discoveries on this programme. We show that the growth model reflects the pragmatic turn of the formalist programme after Gödel and proposes the extension of modern axiomatisation to economics..Von Neumann, Growth model, Formalist revolution, Mathematical formalism, Axiomatics
Higher order energy expansions for some singularly perturbed Neumann problems
No full textWe consider the following singularly perturbed semilinear elliptic problem: \epsilon^{2} \Delta u - u + u^p=0 \ \ \mbox{in} \ \Omega, \quad
u>0 \ \ \mbox{in} \ \ \Omega \quad \mbox{and} \ \frac{\partial u}{\partial \nu} =0 \ \mbox{on} \ \partial \Omega, where \Om is a bounded smooth domain in R^N, \ep>0 is a small constant and p is a subcritical exponent. Let J_\ep [u]:= \int_\Om (\frac{\ep^2}{2} |\nabla u|^2 + \frac{1}{2} u^2- \frac{1}{p+1} u^{p+1}) dx be its energy functional, where u \in H^1 (\Om).
Ni and Takagi proved that for a single boundary spike solution u_\ep, the following asymptotic expansion holds J_\ep [u_\ep] =\ep^{N} \Bigg[ \frac{1}{2} I[w] -c_1 \ep H(P_\ep) + o(\ep)\Bigg], where c_1>0 is a generic constant, P_\ep is the unique local maximum point of u_\ep and H(P_\ep) is the boundary mean curvature function. In this paper, we obtain the following higher order expansion of J_\ep [u_\ep]: J_\ep [u_\ep] =\ep^{N} \Bigg[ \frac{1}{2} I[w] -c_1 \ep H(P_\ep) + \ep^2 [c_2 (H(P_\ep))^2 + c_3 R (P_\ep)]+ o(\ep^2)\Bigg], where c_2, c_3 are generic constants and R(P_\ep) is the Ricci scalar curvature at P_\ep. In particular c_3 >0. Applications of this expansion will be given
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