2,135 research outputs found
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)
A comparison of deflation and the balancing Neumann-Neumann preconditioner
No full textIn this paper we compare various preconditioners for the numerical solution of partial differential equations. We compare the well-known balancing Neumann Neumann preconditioner used in domain decomposition methods with a so-called deflation preconditioner. We prove that the effective condition number of the deflated preconditioned system is always, i.e. for all deflation vectors and all restrictions and prolongations, below the condition number of the system preconditioned by the balancing Neumann-Neumann preconditioner. Even more, we establish that both preconditioners lead to almost the same spectra. The zero eigenvalues of the deflation preconditioned system are replaced by eigenvalues which are one if the balancing Neumann-Neumann preconditioner is used. Moreover, we proved that the A-norm of the errors of the iterates build by the deflation preconditioner is always below the A-norm of the errors of the iterates build by the balancing Neumann-Neumann preconditioner. Additionally, the amount of work of one iteration of the de ation preconditioned system is less than the amount of work of one iteration of the balancing Neumann-Neumann preconditioned system. Finally, we establish that the deflation preconditioner and the balancing Neumann-Neumann preconditioner produces the same iterates if one uses certain starting vectors. Numerical results for porous media flows emphasize the theoretical results.Electrical Engineering, Mathematics and Computer Scienc
Relative Haagerup property for arbitrary von Neumann algebras
No full textWe introduce the relative Haagerup approximation property for a unital, expected inclusion of arbitrary von Neumann algebras and show that if the smaller algebra is finite then the notion only depends on the inclusion itself, and not on the choice of the conditional expectation. Several variations of the definition are shown to be equivalent in this case, and in particular the approximating maps can be chosen to be unital and preserving the reference state. The concept is then applied to amalgamated free products of von Neumann algebras and used to deduce that the standard Haagerup property for a von Neumann algebra is stable under taking free products with amalgamation over finite-dimensional subalgebras. The general results are illustrated by examples coming from q-deformed Hecke-von Neumann algebras and von Neumann algebras of quantum orthogonal groups.Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Analysi
A note on states of von Neumann algebras
No full textsummary:The author proves that on a von Neumann albebra (possibly of uncountable cardinality) there exists a family of states having mutually orthogonal supports (projections) converging to the identity operator
W* algebras as a complete axiomatization of Von-Neumann algebras
No full textDer Author beweist in dieser ausgesprochen tief liegenden Diplomarbeit die Charakterisierung von S. Sakai von Von-Neumann-Algebren A durch die Eigenschaft, dass A neben seiner Struktur als C*-Algebra noch Dualraum eines Banachraumes ist.The author proves in this thesis S. Sakai's characterization of Von-Neumann algebras A by the property, that besides being A C* algebra A is also the dual space of a Banach space
Conformal Dirichlet-Neumann Maps and Poincaré-Einstein Manifolds
No full textA conformal description of Poincaré-Einstein manifolds is developed: these structures are seen to be a special case of a natural weakening of the Einstein condition termed an almost Einstein structure. This is used for two purposes: to shed light on the relationship between the scattering construction of Graham-Zworski and the higher order conformal Dirichlet-Neumann maps of Branson and the author; to sketch a new construction of non-local (Dirichlet-to-Neumann type) conformal operators between tensor bundles
Funeral of theatre director František Neumann in Brno
No full textThe segment captures the funeral of theatre director František Neumann held in Brno on 27 February 1929. The coffin is carried out of the building of the Mahen Theatre and loaded onto a horse-drawn hearse. The funeral procession moves along the streets of Brno towards the railway station, where the coffin is placed in a special funeral carriage. The train leaves for Prostějov, Neumann´s final resting place. The footage includes two versions of the film capturing the same event
Elképzelések a Neumann János Multimédia Központ és Digitális Könyvtárról
No full textA government decree ordered the establishment of the János Neumann MCDL, Hungary. For preliminary preparations, the Ministry of Culture and Education has established the János Neumann Public Association for Cultural Services with the main function to prepare the basic collection of this national cultural organisation and to start its digital library services. The author publishes the Professional contents of the winner study for the acting director's tender invitation of the Public Association.Kormányhatározat rendelkezik a Neumann János Multimédia Központ és Digitális Könyvtár felépítéséről. Az előkészítő feladatok ellátására a Művelődési és Közoktatási Minisztérium létrehozta a Neumann János Kulturális Szolgáltató Közhasznú Társaságot, amelynek legfontosabb célja a majdani nemzeti kulturális intézmény gyűjteményének megalapozása ós a digitális könyvtári szolgáltatások megindítása. A cikk a közhasznú társaság ügyvezető igazgatói pályázatán nyertes munka szakmai részét tartalmazza
Solving integral equations with generalized Neumann kernel using global simpler GMRES for numerical conformal mapping
No full textWe study a numerical approach for solving integral equation with adjoint generalized Neumann kernel related to conformal mapping. Previously, computation of conformal mapping of M + 1 connected regions require solving at least M + 1 integral equations with adjoint generalized Neumann kernel separately. We apply global simpler GMRES which solve nonsymmetric system with multiple right-hand sides to solve M + 1 integral equations simultaneously. We also apply fast multipole method for several matrix vector products in every iteration of global simpler GMRES. Numerical example is given to illustrate the effectiveness of the proposed method
Von Neumann stability conditions for the convection-diffusion equation
No full textA method is presented to easily derive von Neumann stability conditions for a wide variety of time discretization schemes for the convection-diffusion equation. Spatial discretization is by the (c-scheme or the fourth-order central scheme. The use of the method is illustrated by application to multistep, Runge-Kutta and implicit-explicit methods, such as are in current use for flow computations, and for which, with few exceptions, no sufficient von Neumann stability results are available. 1
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