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 Riemann-Hilbert problem with a vanishing coefficient and applications to Toeplitz operators
We study the homogeneous Riemann-Hilbert problem with a vanishing scalar-valued continuous coefficient. We characterize non-existence of nontrivial solutions in the case where the coefficient has its values along several rays starting from the origin. As a consequence, some results on injectivity and existence of eigenvalues of Toeplitz operators in Hardy spaces are obtained.
A Riesz representation theory for completely regular Hausdorff spaces and its applications
Let X be a completely regular Hausdorff space, E and F be Banach spaces. Let Cb(X, E) be the space of all E-valued bounded, continuous functions on X, equipped with the strict topology β. We develop the Riemman-Stieltjes-type Integral representation theory of (β, || · ||F) -continuous operators T : Cb(X, E) → F with respect to the representing Borel operator measures. For X being a k-space, we characterize strongly bounded (β, || · ||F)-continuous operators T : Cb(X, E) → F. As an application, we...
A rigorous approach to relativistic corrections of bound state energies for spin-1/2 particles
A saddle point approach to nonlinear eigenvalue problems
A scattering theory for automorphic functions
A Schur-Horn-Kostant convexity theorem for the diffeomorphism group of the annulus.
A second-order boundary value problem with nonlinear and mixed boundary conditions: existence, uniqueness, and approximation.
A second-order impulsive Cauchy problem.
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 approach to the system with primary and secondary failures.
A Semigroup Structure in the Space of Liftings.
A semigroup-theoretic proof of Poisson's limit law.
A semi-linear elliptic equation in a strip arising in a two-dimensional flame propagation model.
A semilinear elliptic problem involving nonlinear boundary condition and sign-changing potential.
A semilinear equation in
A semilinear perturbation of the identity in Hilbert spaces.
A sequential iteration algorithm with non-monotoneous behaviour in the method of projections onto convex sets
The method of projections onto convex sets to find a point in the intersection of a finite number of closed convex sets in a Euclidean space, may lead to slow convergence of the constructed sequence when that sequence enters some narrow “corridor” between two or more convex sets. A way to leave such corridor consists in taking a big step at different moments during the iteration, because in that way the monotoneous behaviour that is responsible for the slow convergence may be interrupted. In this...
A set of axioms for the degree of a tangent vector field on differentiable manifolds.