Facial Structure of the Sum of Two Compact Convex Sets.
Factoring weakly compact homomorphisms, interpolation of Banach algebras and multilinear interpolation
We review several results on interpolation of Banach algebras and factorization of weakly compact homomorphisms. We also establish a new result on interpolation of multilinear operators.
Factorization in Banach algebras
Factorization in Fréchet spaces
Factorization in some Fréchet algebras of differentiable functions
FF-Banachverbandsalgebren.
Finite dimensionality in socle of Banach algebras.
Finite generation in C*-algebras and Hilbert C*-modules
We characterize C*-algebras and C*-modules such that every maximal right ideal (resp. right submodule) is algebraically finitely generated. In particular, C*-algebras satisfy the Dales-Żelazko conjecture.
Finite rank elements in semisimple Banach algebras
Let A be a semisimple Banach algebra. We define the rank of a nonzero element a in the socle of A to be the minimum of the number of minimal left ideals whose sum contains a. Several characterizations of rank are proved.
Finite spectra and quasinilpotent equivalence in Banach algebras
This paper further investigates the implications of quasinilpotent equivalence for (pairs of) elements belonging to the socle of a semisimple Banach algebra. Specifically, not only does quasinilpotent equivalence of two socle elements imply spectral equality, but also the trace, determinant and spectral multiplicities of the elements must agree. It is hence shown that quasinilpotent equivalence is established by a weaker formula (than that of the spectral semidistance). More generally, in the second...
Finite-dimensional ideals in Banach algebras
Finite-dimensional Lie subalgebras of algebras with continuous inversion
We investigate the finite-dimensional Lie groups whose points are separated by the continuous homomorphisms into groups of invertible elements of locally convex algebras with continuous inversion that satisfy an appropriate completeness condition. We find that these are precisely the linear Lie groups, that is, the Lie groups which can be faithfully represented as matrix groups. Our method relies on proving that certain finite-dimensional Lie subalgebras of algebras with continuous inversion commute...
Finiteness properties of topological algebras, I
First results on spectrally bounded operators
A linear mapping T from a subspace E of a Banach algebra into another Banach algebra is defined to be spectrally bounded if there is a constant M ≥ 0 such that r(Tx) ≤ Mr(x) for all x ∈ E, where r(·) denotes the spectral radius. We study some basic properties of this class of operators, which are sometimes analogous to, sometimes very different from, those of bounded operators between Banach spaces.
Fixed point characterization of left amenable Lau algebras.
Fixed points and stability of an additive functional equation of -Apollonius type in -algebras.
Fonctions analytiques de contractions topologiques dans les algèbres hermitiennes.
In this paper we define a functional calculus, for harmonic vector valued functions, in Banach algebras with continuous involution. Using this calculus, we generalize in two settings the results of Shih and Tan on analytic functions of topological proper contractions to analytic vector valued functions in Hermitian Banach algebras. We also make an extension of other results such as Schwarz's lemma and Pick's theorem.
Fonctions entières et théorèmes de Banach-Steinhaus dans certaines algèbres complètes
Fonctions harmoniques opérant sur les algèbres de Banach involutives
Nous introduisons un calcul fonctionnel pour les fonctions harmoniques sur un ouvert du plan complexe et à valeurs dans une algèbre de Banach à involution continue. Ensuite, nous donnons dans les algèbres hermitiennes deux extensions des théorèmes de von Neumann et de Ky Fan sur les contractions. Nous obtenons également les analogues du lemme de Schwarz et du théorème de Pick.
Formes multiplicatives à valeurs dans le spectre