De nouveaux espaces de Banach sans la propriété d'approximation
Decay of spatial correlations in thermal states
Decoherence in pre-symmetric spaces.
Decomposition and disintegration of positive definite kernels on convex *-semigroups
The paper deals with operator-valued positive definite kernels on a convex *-semigroup whose Kolmogorov-Aronszajn type factorizations induce *-semigroups of bounded shift operators. Any such kernel Φ has a canonical decomposition into a degenerate and a nondegenerate part. In case is commutative, Φ can be disintegrated with respect to some tight positive operator-valued measure defined on the characters of if and only if Φ is nondegenerate. It is proved that a representing measure of a positive...
Décomposition et classification des systèmes dynamiques
Decomposition of Positive Projections on C*-Algebras.
Decomposition of unbounded derivations into invariant and approximately inner parts.
Decompositions of Beurling type for E₀-semigroups
We define tensor product decompositions of E₀-semigroups with a structure analogous to a classical theorem of Beurling. Such decompositions can be characterized by adaptedness and exactness of unitary cocycles. For CCR-flows we show that such cocycles are convergent.
Decompositions of operator-valued functions in Hilbert spaces
Deformation of involution and multiplication in a C*-algebra
We investigate the deformations of involution and multiplication in a unital C*-algebra when its norm is fixed. Our main result is to present all multiplications and involutions on a given C*-algebra 𝓐 under which 𝓐 is still a C*-algebra when we keep the norm unchanged. For each invertible element a ∈ 𝓐 we also introduce an involution and a multiplication making 𝓐 into a C*-algebra in which a becomes a positive element. Further, we give a necessary and sufficient condition for the center of...
Deformation Theory (Lecture Notes)
First three sections of this overview paper cover classical topics of deformation theory of associative algebras and necessary background material. We then analyze algebraic structures of the Hochschild cohomology and describe the relation between deformations and solutions of the corresponding Maurer-Cartan equation. In Section we generalize the Maurer-Cartan equation to strongly homotopy Lie algebras and prove the homotopy invariance of the moduli space of solutions of this equation. In the last...
Déformations de -algèbres de Hopf
Density of the self-adjoint elements with finite spectrum in an irrational rotation C*-algebra.
Der Primidealraum der C*-Algebra und die unzerlegebaren Charaktere der Gruppe GI (...,q).
Derivation Algebras of JB-Algebras.
Derivations, dynamical systems, and spectral restrictions.
Derivations of simple -algebras. II
Derivatons of Jordan C*-algebras.
Determinant lines, von Neumann algebras and L2 torsion.
Diagonality in C*-Algebras.