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C * algebras associated with von Neumann algebras

Tullio G. Ceccherini-Silberstein (1999)

Bollettino dell'Unione Matematica Italiana

Ad un'algebra di von Neumann separabile M , in forma standard su di uno spazio di Hilbert H , si associa la C * algebra O M definita come la C * algebra O U M costituita dai punti fissi dell'algebra di Cuntz generalizzata O H mediante l'azione canonica del gruppo U M degli unitari di M . Si dà una caratterizzazione di O M nel caso in cui M è un fattore iniettivo. In seguito, come applicazione della teoria dei sistemi asintoticamente abeliani, si mostra che, se ω è uno stato vettoriale normale e fedele di M , la restrizione...

Caractérisation des espaces vectoriels ordonnés sous-jacents aux algèbres de von Neumann

Alain Connes (1974)

Annales de l'institut Fourier

Nous démontrons que la catégorie de von Neumann est équivalente à la catégorie des cônes autopolaires, facialement homogènes, complexes. Un cône dans un espace hilbertien réel est dit : 1) facialement homogène quand pour toute face F de l’opérateur δ = (Projection sur F - F ) - (Projection sur F - F ) est une dérivation de (i.e. e t δ = t R ) ; 2) complexe quand on s’est donné une structure d’algèbre de Lie complexe sur l’algèbre de Lie réelle des dérivations de , modulo son centre. Nous caractérisons les espaces...

Central sequences in the factor associated with Thompson’s group F

Paul Jolissaint (1998)

Annales de l'institut Fourier

We prove that the type II 1 factor L ( F ) generated by the regular representation of F is isomorphic to its tensor product with the hyperfinite type II 1 factor. This implies that the unitary group of L ( F ) is contractible with respect to the topology defined by the natural Hilbertian norm.

Chain rules for canonical state extensions on von Neumann algebras

Carlo Cecchini, Dénes Petz (1993)

Colloquium Mathematicae

In previous papers we introduced and studied the extension of a state defined on a von Neumann subalgebra to the whole of the von Neumann algebra with respect to a given state. This was done by using the standard form of von Neumann algebras. In the case of the existence of a norm one projection from the algebra to the subalgebra preserving the given state our construction is simply equivalent to taking the composition with the norm one projection. In this paper we study couples of von Neumann subalgebras...

Commutators associated to a subfactor and its relative commutants

Hsiang-Ping Huang (2002)

Annales de l’institut Fourier

Let N M be an inclusion of I I 1 factors with finite Jones index. Then M = ( N ' M ) [ N , M ] as a vector space. Here [ N , M ] denotes the vector space spanned by the commutators of the form [ a , b ] where a N , b M .

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