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Pseudodifferential operators on non-quasianalytic classes of Beurling type

C. Fernández, A. Galbis, D. Jornet (2005)

Studia Mathematica

We introduce pseudodifferential operators (of infinite order) in the framework of non-quasianalytic classes of Beurling type. We prove that such an operator with (distributional) kernel in a given Beurling class ( ω ) ' is pseudo-local and can be locally decomposed, modulo a smoothing operator, as the composition of a pseudodifferential operator of finite order and an ultradifferential operator with constant coefficients in the sense of Komatsu, both operators with kernel in the same class ( ω ) ' . We also...

Quantum Itô algebra and quantum martingale

Viacheslav Belavkin, Un Cig Ji (2007)

Banach Center Publications

In this paper, we study a representation of the quantum Itô algebra in Fock space and then by using a noncommutative Radon-Nikodym type theorem we study the density operators of output states as quantum martingales, where the output states are absolutely continuous with respect to an input (vacuum) state. Then by applying quantum martingale representation we prove that the density operators of regular, absolutely continuous output states belong to the commutant of the ⋆-algebra parameterizing the...

Quantum Lévy-type Laplacian and associated stochastic differential equations

A. Barhoumi, H. Ouerdiane (2006)

Banach Center Publications

We study a quantum extension of the Lévy Laplacian, so-called quantum Lévy-type Laplacian, to the nuclear algebra of operators on spaces of entire functions. We give several examples of the action of the quantum Lévy-type Laplacian on basic operators and we study a quantum white noise convolution differential equation involving the quantum Lévy-type Laplacian.

Quelques théorèmes de décomposition des ultradistributions

André Lambert (1979)

Annales de l'institut Fourier

Deux décompositions d’une fonctionnelle T d’un espace d’ultra-distributions sont étudiées. La première fait intervenir une série convergente de dérivées de mesures dont on montre que les supports peuvent être pris inclus dans le support T . La seconde consiste à exprimer T comme somme de fonctionnelles du même espace portées par les éléments d’une partition du support de T . Dans les deux cas on a recours à des concepts de régularité et de séparation régulière d’ensembles fermés de R ν qui relient la...

Range of the horocyclic Radon transform on trees

Enrico Casadio Tarabusi, Joel M. Cohen, Flavia Colonna (2000)

Annales de l'institut Fourier

In this paper we study the Radon transform R on the set of horocycles of a homogeneous tree T , and describe its image on various function spaces. We show that the functions of compact support on that satisfy two explicit Radon conditions constitute the image under R of functions of finite support on T . We extend these results to spaces of functions with suitable decay on T , whose image under R satisfies corresponding decay conditions and contains distributions on that are not defined pointwise....

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