Separation and disconjugacy.
An eigenvalue criterion for hypercyclicity due to the first author is improved. As a consequence, some new sufficient conditions for a sequence of infinite order linear differential operators to be hypercyclic on the space of holomorphic functions on certain domains of are shown. Moreover, several necessary conditions are furnished. The equicontinuity of a family of operators as above is also studied, and it is characterized if the domain is . The results obtained extend or improve earlier work...
The paper is devoted to a careful analysis of the shape-preserving properties of the strongly continuous semigroup generated by a particular second-order differential operator, with particular emphasis on the preservation of higher order convexity and Lipschitz classes. In addition, the asymptotic behaviour of the semigroup is investigated as well. The operator considered is of interest, since it is a unidimensional Black-Scholes operator so that our results provide qualitative information on the...
Dans la première partie on caractérise les opérateurs différentiels invariants sur un groupe de Lie compact qui possèdent diverses propriétés de résolubilité analytiques : pour cela on développe en séries de Fourier les fonctions analytiques et les hyperfonctions sur le groupe.La deuxième partie est l’étude de la résolubilité des opérateurs invariants sur un groupe complexe réductif dans l’espace des fonctions holomorphes ; on développe celles-ci en série de “Laurent” suivant un sous-groupe compact...