Applications of harmonic functional calculus in a quotient involutive Banach algebra. (Applications du calcul fonctionnel harmonique dans une algèbre de Banach involutive quotient.)
Spherical designs constitute sets of points distributed on spheres in a regular way. They can be used to construct finite-dimensional normed spaces which are extreme in some sense: having large projection constants, big or small Banach-Mazur distance to Hilbert spaces or -spaces. These examples provide concrete illustrations of results obtained by more powerful probabilistic techniques which, however, do not exhibit explicit examples. We give a survey of such constructions where the geometric invariants...
2000 Mathematics Subject Classification: 46A30, 54C60, 90C26.In this paper we prove two results of nonsmooth analysis involving the Fréchet subdifferential. One of these results provides a necessary optimality condition for an optimization problem which arise naturally from a class of wide studied problems. In the second result we establish a sufficient condition for the metric regularity of a set-valued map without continuity assumptions.
We apply Gromov’s ham sandwich method to get: (1) domain monotonicity (up to a multiplicative constant factor); (2) reverse domain monotonicity (up to a multiplicative constant factor); and (3) universal inequalities for Neumann eigenvalues of the Laplacian on bounded convex domains in Euclidean space.
Let be an algebraically closed field of characteristic zero, complete for an ultrametric absolute value. We apply the -adic Nevanlinna theory to functional equations of the form , where , are meromorphic functions in , or in an “open disk”, satisfying conditions on the order of its zeros and poles. In various cases we show that and must be constant when they are meromorphic in all , or they must be quotients of bounded functions when they are meromorphic in an “open disk”. In particular,...
We apply Aupetit's scarcity theorem to obtain stronger versions of many spectral-theoretical results in ordered Banach algebras in which the algebra cone has generating properties.
Soient , des espaces de Banach , des espaces d’Orlicz, on définit les applications sommantes de dans . On montre que de telles applications sont radonifiantes de dans .On donne une factorisation caractéristique des applications sommantes.
The problem of when derivations (and their powers) have the range in the Jacobson radical is considered. The proofs are based on the density theorem for derivations.