On a local ergodic theorem
On a non-linear semi-group associated with stochastic optimal control and its excessive majorant
On a regularizing effect of Schrödinger type groups
On a type of matrix semigroup.
On a universality property of some abelian Polish groups
We show that every abelian Polish group is the topological factor group of a closed subgroup of the full unitary group of a separable Hilbert space with the strong operator topology. It follows that all orbit equivalence relations induced by abelian Polish group actions are Borel reducible to some orbit equivalence relations induced by actions of the unitary group.
On an exponential-cosine operator-valued functional equation.
On an Exponential-Cosine Operator-Valued Functional Equation. (Short Communication).
On an th-order infinitesimal generator and time-dependent operator differential equation with a strongly almost periodic solution.
On analytic semigroups and cosine functions in Banach spaces
If A generates a bounded cosine function on a Banach space X then the negative square root B of A generates a holomorphic semigroup, and this semigroup is the conjugate potential transform of the cosine function. This connection is studied in detail, and it is used for a characterization of cosine function generators in terms of growth conditions on the semigroup generated by B. The characterization relies on new results on the inversion of the vector-valued conjugate potential transform.
On Co-Semigroups of Lattice Homomorphisms on a Banach Lattice.
On cosine operator functions and one-parameter groups of operators
On exit laws for subordinated semigroups by means of -subordinators
We study the integral representation of potentials by exit laws in the framework of sub-Markovian semigroups of bounded operators acting on . We mainly investigate subordinated semigroups in the Bochner sense by means of -subordinators. By considering the one-sided stable subordinators, we deduce an integral representation for the original semigroup.
On extrapolation spaces
Si definisce un nuovo tipo di spazi a partire da un dato spazio di Banach e da un operatore lineare in . Tali spazi si possono pensare come spazi di interpolazione con negativo.
On group decompositions of bounded cosine sequences
A two-sided sequence with values in a complex unital Banach algebra is a cosine sequence if it satisfies for any n,m ∈ ℤ with c₀ equal to the unity of the algebra. A cosine sequence is bounded if . A (bounded) group decomposition for a cosine sequence is a representation of c as for every n ∈ ℤ, where b is an invertible element of the algebra (satisfying , respectively). It is known that every bounded cosine sequence possesses a universally defined group decomposition, here referred...
On Lattice Isomorphisms with Positive Real Spectrum and Groups of Positive Operators.
On local ergodic theorems for positive semigroups
On Markovian cocycle perturbations in classical and quantum probability.
On maximal compact subsemigroups of the endomorphism semigroup of an n-dimensional complex vector space.
On operator bands
A multiplicative semigroup of idempotent operators is called an operator band. We prove that for each K>1 there exists an irreducible operator band on the Hilbert space which is norm-bounded by K. This implies that there exists an irreducible operator band on a Banach space such that each member has operator norm equal to 1. Given a positive integer r, we introduce a notion of weak r-transitivity of a set of bounded operators on a Banach space. We construct an operator band on that is weakly...
On Operators with Bounded Imaginary Powers in Banach Spaces.