The search session has expired. Please query the service again.

The search session has expired. Please query the service again.

Displaying 1601 – 1620 of 1952

Showing per page

On the traces of W2,p(Ω) for a Lipschitz domain.

Ricardo G. Durán, María Amelia Muschietti (2001)

Revista Matemática Complutense

We extend to the case 1 < p the results obtained by Geymonat and Krasucki for p = 2 on the characterization of the traces of W2,p(Ω) for a bounded Lipschitz domain.

On the transient and recurrent parts of a quantum Markov semigroup

Veronica Umanità (2006)

Banach Center Publications

We define the transient and recurrent parts of a quantum Markov semigroup 𝓣 on a von Neumann algebra 𝓐 and we show that, when 𝓐 is σ-finite, we can write 𝓣 as the sum of such semigroups. Moreover, if 𝓣 is the countable direct sum of irreducible semigroups each with a unique faithful normal invariant state ρₙ, we find conditions under which any normal invariant state is a convex combination of ρₙ's.

On the type constants with respect to systems of characters of a compact abelian group

Aicke Hinrichs (1996)

Studia Mathematica

We prove that there exists an absolute constant c such that for any positive integer n and any system Φ of 2 n characters of a compact abelian group, 2 - n / 2 t Φ ( T ) c n - 1 / 2 t n ( T ) , where T is an arbitrary operator between Banach spaces, t Φ ( T ) is the type norm of T with respect to Φ and t n ( T ) is the usual Rademacher type-2 norm computed with n vectors. For the system of the first 2 n Walsh functions this is even true with c=1. This result combined with known properties of such type norms provides easy access to quantitative versions of...

On the ultrametric Stone-Weierstrass theorem and Mahler's expansion

Paul-Jean Cahen, Jean-Luc Chabert (2002)

Journal de théorie des nombres de Bordeaux

We describe an ultrametric version of the Stone-Weierstrass theorem, without any assumption on the residue field. If E is a subset of a rank-one valuation domain V , we show that the ring of polynomial functions is dense in the ring of continuous functions from E to V if and only if the topological closure E ^ of E in the completion V ^ of V is compact. We then show how to expand continuous functions in sums of polynomials.

On the Uniform Convergence of Partial Dunkl Integrals in Besov-Dunkl Spaces

Abdelkefi, Chokri, Sifi, Mohamed (2006)

Fractional Calculus and Applied Analysis

2000 Mathematics Subject Classification: 44A15, 44A35, 46E30In this paper we prove that the partial Dunkl integral ST(f) of f converges to f, as T → +∞ in L^∞(νµ) and we show that the Dunkl transform Fµ(f) of f is in L^1(νµ) when f belongs to a suitable Besov-Dunkl space. We also give sufficient conditions on a function f in order that the Dunkl transform Fµ(f) of f is in a L^p -space.* Supported by 04/UR/15-02.

Currently displaying 1601 – 1620 of 1952