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Surjectivity of convolution operators on spaces of ultradifferentiable functions of Roumieu type

Thomas Meyer (1997)

Studia Mathematica

Let ε ω ( I ) denote the space of all ω-ultradifferentiable functions of Roumieu type on an open interval I in ℝ. In the special case ω(t) = t we get the real-analytic functions on I. For μ ε ω ( I ) ' with s u p p ( μ ) = 0 one can define the convolution operator T μ : ε ω ( I ) ε ω ( I ) , T μ ( f ) ( x ) : = μ , f ( x - · ) . We give a characterization of the surjectivity of T μ for quasianalytic classes ε ω ( I ) , where I = ℝ or I is an open, bounded interval in ℝ. This characterization is given in terms of the distribution of zeros of the Fourier Laplace transform μ ^ of μ.

Swiss cheeses, rational approximation and universal plane curves

J. F. Feinstein, M. J. Heath (2010)

Studia Mathematica

We consider the compact plane sets known as Swiss cheese sets, which are a useful source of examples in the theory of uniform algebras and rational approximation. We develop a theory of allocation maps connected to such sets and we use this theory to modify examples previously constructed in the literature to obtain examples homeomorphic to the Sierpiński carpet. Our techniques also allow us to avoid certain technical difficulties in the literature.

Symmetric Banach *-algebras: invariance of spectrum

Bruce Barnes (2000)

Studia Mathematica

Let A be a Banach *-algebra which is a subalgebra of a Banach algebra B. In this paper, assuming that A is symmetric, various conditions are given which imply that A is inverse closed in B.

Symmetric Bessel multipliers

Khadija Houissa, Mohamed Sifi (2012)

Colloquium Mathematicae

We study the L p -boundedness of linear and bilinear multipliers for the symmetric Bessel transform.

Symmetric stochastic matrices with given row sums.

Ryszard Grzaslewicz (1990)

Revista Matemática de la Universidad Complutense de Madrid

Characterizations of extreme infinite symmetric stochastic matrices with respect to arbitrary non-negative vector r are given.

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