Normed combinatorial homology and noncommutative tori.
Normed groups and their applications in noncommutative differential geometry.
Normes de Sobolev et convoluteurs bornés sur
Un groupe localement compact muni d’une fonction-longueur a la propriété par rapport à si toute fonction à décroissance rapide sur définit un convoluteur borné sur . Nous donnons une condition suffisante assez générale pour que le couple ait la propriété . Pour un tel couple, nous caractérisons les fonctions de type positif sur faiblement associées à la représentation régulière gauche et, dans le cas discret, nous considérons les propriétés d’approximation de l’algèbre de Fourier...
Note on a construction of unbounded measures on a nonseparable Hilbert space quantum logic
Notes on a class of simple C*-algebras with real rank zero.
A construction method is presented for a class of simple C*-algebras whose basic properties -including their real ranks- can be computed relatively easily, using linear algebra. A numerival invariant attached to the construction determines wether a given algebra has real rank 0 or 1. Moreover, these algebras all have stable rank 1, and each nonzero hereditary sub-C*-algebra contains a nonzero projection, yet there are examples in which the linear span of the projections is not dense. (This phenomenon...
Notes on automorphisms of ultrapowers of II₁ factors
In functional analysis, approximative properties of an object become precise in its ultrapower. We discuss this idea and its consequences for automorphisms of II₁ factors. Here are some sample results: (1) an automorphism is approximately inner if and only if its ultrapower is ℵ₀-locally inner; (2) the ultrapower of an outer automorphism is always outer; (3) for unital *-homomorphisms from a separable nuclear C*-algebra into an ultrapower of a II₁ factor, equality of the induced traces implies unitary...
Notes on Cartan subalgebras in type II... factors.
Notes on modular conjugations of von Neumann factors.
Nuclear JC-algebras and tensor products of types.