The application of fixed point theorems to global nonlinear controllability problems.
The boundary spectrum of linear operators in finite-dimensional spaces
The Cesàro and related operators, a survey
We provide a survey of properties of the Cesàro operator on Hardy and weighted Bergman spaces, along with its connections to semigroups of weighted composition operators. We also describe recent developments regarding Cesàro-like operators and indicate some open questions and directions of future research.
The classical field limit of non-relativistic bosons. II. Asymptotic expansions for general potentials
The Clifford algebra and the Spinor group of a Hilbert space
The embeddability of an invertible measure.
The fundamental solutions for fractional evolution equations of parabolic type.
The group of L²-isometries on H¹₀
Let Ω be an open subset of ℝⁿ. Let L² = L²(Ω,dx) and H¹₀ = H¹₀(Ω) be the standard Lebesgue and Sobolev spaces of complex-valued functions. The aim of this paper is to study the group of invertible operators on H¹₀ which preserve the L²-inner product. When Ω is bounded and ∂Ω is smooth, this group acts as the intertwiner of the H¹₀ solutions of the non-homogeneous Helmholtz equation u - Δu = f, . We show that is a real Banach-Lie group, whose Lie algebra is (i times) the space of symmetrizable operators....
The Hadamard product and related dilations
The H-theorem for Boltzmann type equations.
The linear-quadratic optimal control problem for delay differential equations
In questo lavoro si considera il problema del controllo ottimo per un'equazione lineare con ritardo in uno spazio di Hilbert, con costo quadratico. Si dimostra che il problema della sintesi si traduce in una equazione di Riccati in uno opportuno spazio prodotto e si prova che tale equazione ammette un’unica soluzione.
The Method of Stationary Phase for Once Integrated Group
The Projection onto the Center of Operators in a Banach Lattice.
The RAGE theorem in Banach spaces.
The Rockland condition for nondifferential convolution operators II
The semigroup of Fredholm operators.
The Sobolev-Besov imbedding theorem from the viewpoint of semi-groups of operators
The solution operator for a partial differential equation with delay
Viene dimostrata l’esistenza e l’unicità globale della soluzione di un’equazione funzionale in uno spazio di Hilbert e si caratterizza il generatore infinitesimale del semigruppo ad essa associato. Il risultato è applicato ad equazioni integrodifferenziali a derivate parziali di tipo parabolico in cui compaiono argomenti con ritardo (discreto e continuo) nelle derivate spaziali di ordine massimo.
The spectral mapping theorem for one-parameter groups of positive operators on C0(X).
The theory of stationary vector-valued measures over R.