A Note on the Product of Random Elements of a Semigroup.
A notion of analytic generator for groups of unbounded operators
We introduce a notion of analytic generator for groups of unbounded operators, on Banach modules, arising from Esterle’s quasimultiplier theory. Characterizations of analytic generators are given in terms of the existence of certain functional calculi. This extends recent results about C₀ groups of bounded operators. The theory is applicable to sectorial operators, representations of , and integrated groups.
A parabolic - elliptic variational inequality.
A perturbation theorem for semigroups of linear operators
A Perturbation Theorem for the Essential Spectral Radius of Strongly Continuous Semigroups.
A property of semigroups on metric spaces.
A quantitative asymptotic theorem for contraction semigroups with countable unitary spectrum
Let T be a semigroup of linear contractions on a Banach space X, and let . Then is the annihilator of the bounded trajectories of T*. If the unitary spectrum of T is countable, then is the annihilator of the unitary eigenvectors of T*, and for each x in X.
A remark on harmonic analysis of strongly almost-periodic groups of linear operators
A representation formula for strongly continuous cosine families. (Short Communication).
A representation formula for strongly continuous cosine families.
A result on two one-parameter groups of automorphisms.
A Riccati equation arising in a boundary control problem for distributed parameters
Si prova resistenza locale della soluzione di una equazione di Riccati che si incontra in un problema di controllo ottimale. In ipotesi di regolarità per il costo si prova resistenza globale. Il problema astratto considerato è il modello di alcuni problemi di controllo ottimale governati da equazioni paraboliche con controllo sulla frontiera.
A Schur-Horn-Kostant convexity theorem for the diffeomorphism group of the annulus.
A semigroup analogue of the Fonf-Lin-Wojtaszczyk ergodic characterization of reflexive Banach spaces with a basis
In analogy to a recent result by V. Fonf, M. Lin, and P. Wojtaszczyk, we prove the following characterizations of a Banach space X with a basis. (i) X is finite-dimensional if and only if every bounded, uniformly continuous, mean ergodic semigroup on X is uniformly mean ergodic. (ii) X is reflexive if and only if every bounded strongly continuous semigroup is mean ergodic if and only if every bounded uniformly continuous semigroup on X is mean ergodic.
A Semigroup Structure in the Space of Liftings.
A semigroup-theoretic proof of Poisson's limit law.
A spectral mapping theorem for evolution semigroups on asymptotically almost periodic functions defined on the half line.
A stability theorem of the Navier-Stokes flow past a rotating body
In this paper, a stability theorem of the Navier-Stokes flow past a rotating body is reported. Concerning the linearized problem, the proofs of the generation of a C₀ semigroup and its decay properties are sketched.
A structure theory for isometric representations of a class of semigroups.
A sufficient condition for a group of homeomorphisms to be affine.