Results 31 to 40 of about 1,971 (100)

A direct proof of Sobolev embeddings for quasi‐homogeneous Lizorkin–Triebel spaces with mixed norms

open access: yesJournal of Function Spaces, Volume 5, Issue 2, Page 183-198, 2007., 2007
The article deals with a simplified proof of the Sobolev embedding theorem for Lizorkin–Triebel spaces (that contain the Lp‐Sobolev spaces Hps as special cases). The method extends to a proof of the corresponding fact for general Lizorkin–Triebel spaces based on mixed Lp‐norms.
Jon Johnsen   +2 more
wiley   +1 more source

Integro-differential systems with variable exponents of nonlinearity

open access: yesOpen Mathematics, 2017
Some nonlinear integro-differential equations of fourth order with variable exponents of the nonlinearity are considered. The initial-boundary value problem for these equations is investigated and the existence theorem for the problem is proved.
Buhrii Oleh, Buhrii Nataliya
doaj   +1 more source

New classes of rearrangement‐invariant spaces appearing in extreme cases of weak interpolation

open access: yesJournal of Function Spaces, Volume 4, Issue 3, Page 275-304, 2006., 2006
We study weak type interpolation for ultrasymmetric spaces L?,E i.e., having the norm ??(t)f*(t)?E˜, where ?(t) is any quasiconcave function and E˜ is arbitrary rearrangement‐invariant space with respect to the measure d t /t. When spaces L?,E are not “too close” to the endpoint spaces of interpolation (in the sense of Boyd), the optimal interpolation ...
Evgeniy Pustylnik   +2 more
wiley   +1 more source

The Lusin Theorem and Horizontal Graphs in the Heisenberg Group

open access: yesAnalysis and Geometry in Metric Spaces, 2013
In this paper we prove that every collection of measurable functions fα , |α| = m, coincides a.e. withmth order derivatives of a function g ∈ Cm−1 whose derivatives of order m − 1 may have any modulus of continuity weaker than that of a Lipschitz ...
Hajłasz Piotr, Mirra Jacob
doaj   +1 more source

Admissibility versus Ap-Conditions on Regular Trees

open access: yesAnalysis and Geometry in Metric Spaces, 2020
We show that the combination of doubling and (1, p)-Poincaré inequality is equivalent to a version of the Ap-condition on rooted K-ary trees.
Nguyen Khanh Ngoc, Wang Zhuang
doaj   +1 more source

Modulation spaces Mp,q for 0 < p, q?8

open access: yesJournal of Function Spaces, Volume 4, Issue 3, Page 329-341, 2006., 2006
The purpose of this paper is to construct modulation spaces Mp,q(Rd) for general 0 < p, q?8, which coincide with the usual modulation spaces when 1?p,q?8, and study their basic properties including their completeness. Given any g?S(Rd) such that supp g ???{?||?|?1} and ?k?Zd g (?-ak)=1, our modulation space consists of all tempered distributions f such
Masaharu Kobayashi, Hans Triebel
wiley   +1 more source

Characterization of Riesz and Bessel potentials on variable Lebesgue spaces

open access: yesJournal of Function Spaces, Volume 4, Issue 2, Page 113-144, 2006., 2006
Riesz and Bessel potential spaces are studied within the framework of the Lebesgue spaces with variable exponent. It is shown that the spaces of these potentials can be characterized in terms of convergence of hypersingular integrals, if one assumes that the exponent satisfies natural regularity conditions. As a consequence of this characterization, we
Alexandre Almeida   +2 more
wiley   +1 more source

Sobolev type inequalities in ultrasymmetric spaces with applications to Orlicz‐Sobolev embeddings

open access: yesJournal of Function Spaces, Volume 3, Issue 2, Page 183-208, 2005., 2005
Let Dkf mean the vector composed by all partial derivatives of order k of a function f(x), x ∈ Ω ⊂ ℝn. Given a Banach function space A, we look for a possibly small space B such that ‖f‖B≤c‖|Dkf|‖A for all f∈C0k(Ω). The estimates obtained are applied to ultrasymmetric spaces A = Lφ,E, B = Lψ,E, giving some optimal (or rather sharp) relations between ...
Evgeniy Pustylnik, Lech Maligranda
wiley   +1 more source

Domains of pseudo‐differential operators: a case for the Triebel‐Lizorkin spaces

open access: yesJournal of Function Spaces, Volume 3, Issue 3, Page 263-286, 2005., 2005
The main result is that every pseudo‐differential operator of type 1, 1 and order d is continuous from the Triebel‐Lizorkin space Fp,1d to Lp, 1 ≤ p≺∞, and that this is optimal within the Besov and Triebel‐Lizorkin scales. The proof also leads to the known continuity for s≻d, while for all real s the sufficiency of Hörmander′s condition on the twisted ...
Jon Johnsen, Victor Burenkov
wiley   +1 more source

Approximation theory for weighted Sobolev spaces on curves [PDF]

open access: yes, 2001
17 pages, no figures.-- MSC2000 codes: 41A10, 46E35, 46G10.MR#: MR1882649 (2003c:42002)In this paper we present a definition of weighted Sobolev spaces on curves and find general conditions under which the spaces are complete.
Pestana, Domingo   +3 more
core   +2 more sources

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