Über das Synthese-Problem fur nilpotente Liesche Gruppen.
Über den Satz von Weil-Cartier.
Über den Satz von Wiener und Lokalkompakte Gruppen
Über den Typenkonvergenzsatz auf zusammenhängenden Lie Gruppen.
Über die Integrierbarkeit von Fourier-Transformierten auf Gruppen. Teil I. Stetige Funktionen mit kompaktem Träger und eine Bemerkung über hyperbolische Differentialoperatoren.
Über ein Problem von Reiter und ein Problem von Derighetti zur Eigenschaft P... lokalkompakter Gruppen
Über eine algebraische Ausnutzung der messbaren Transformationen
Über eine Zerlegung des Haarschen Maßes auf kompakten Gruppen.
Über Faltungshalbgruppen von Wahrscheinlichkeitsmaßen II. Einige Klassen topologischer Gruppen.
Über Fortsetzung positiv definiter Funktionen.
Über Integralzerlegungen von Darstellungen nilpotenter Liegruppen.
UC-sets in the dual object of compact groups
Umbral calculus and cancellative semigroup algebras.
Un ensemble remarquable du point de vue de l’analyse de Fourier sur
Un théorème limite central dans un hypergroupe bidimensionnel
Unbounded harmonic functions on homogeneous manifolds of negative curvature
We study unbounded harmonic functions for a second order differential operator on a homogeneous manifold of negative curvature which is a semidirect product of a nilpotent Lie group N and A = ℝ⁺. We prove that if F is harmonic and satisfies some growth condition then F has an asymptotic expansion as a → 0 with coefficients from 𝓓'(N). Then we single out a set of at most two of these coefficients which determine F. Then using asymptotic expansions we are able to prove some theorems...
Unbounded Lebesgue Constants on Compact Groups.
Uncertainty principles for the Schrödinger equation on Riemannian symmetric spaces of the noncompact type
Let be a Riemannian symmetric space of the noncompact type. We prove that the solution of the time-dependent Schrödinger equation on with square integrable initial condition is identically zero at all times whenever and the solution at a time are simultaneously very rapidly decreasing. The stated condition of rapid decrease is of Beurling type. Conditions respectively of Gelfand-Shilov, Cowling-Price and Hardy type are deduced.
Uncertainty principles for the Weinstein transform
The Weinstein transform satisfies some uncertainty principles similar to the Euclidean Fourier transform. A generalization and a variant of Cowling-Price theorem, Miyachi's theorem, Beurling's theorem, and Donoho-Stark's uncertainty principle are obtained for the Weinstein transform.
Unconditionality, Fourier multipliers and Schur multipliers
Let G be an infinite locally compact abelian group and X be a Banach space. We show that if every bounded Fourier multiplier T on L²(G) has the property that is bounded on L²(G,X) then X is isomorphic to a Hilbert space. Moreover, we prove that if 1 < p < ∞, p ≠ 2, then there exists a bounded Fourier multiplier on which is not completely bounded. Finally, we examine unconditionality from the point of view of Schur multipliers. More precisely, we give several necessary and sufficient conditions...