Structured Populations, Linear Semigrous and Positivity.
Study of a complete abstract differential equation of elliptic type with variable operator coefficients, I.
Su un ampliamento della teorìa degli operatori lineari invarianti rispetto ad un gruppo di congruenze
Let be an open subset of , the linear space of -vector valued functions defined on , a group of orthogonal matrices mapping onto itself and a linear representation of order of . A suitable group of linear operators of is introduced which leads to a general definition of -invariant linear operator with respect to . When is a finite group, projection operators are explicitly obtained which define a "maximal" decomposition of the function space into a direct sum of subspaces...
Sur la théorie de Littlewood-Paley-Stein, d'après Coifman-Rochberg-Weiss et Cowling
Sur l'approximation des réduites
Sur les inégalités de Sobolev logarithmiques, I
Sur les inégalités de Sobolev logarithmiques, II
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.