Results 41 to 50 of about 1,954 (101)
Sobolev type inequalities in ultrasymmetric spaces with applications to Orlicz‐Sobolev embeddings
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
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]
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
Sobolev spaces, Lebesgue points and maximal functions
In this note we study boundedness of a large class of maximal operators in Sobolev spaces that includes the spherical maximal operator. We also study the size of the set of Lebesgue points with respect to convergence associated with such maximal ...
Hajlasz, Piotr, Liu, Zhuomin
core +1 more source
Box dimension, oscillation and smoothness in function spaces
The aim of this paper is twofold. First we relate upper and lower box dimensions with oscillation spaces, and we develop embeddings or inclusions between oscillation spaces and Besov spaces. Secondly, given a point in the (1p, s)‐plane we determine maximal and minimal values for the upper box dimension (also the maximal value for lower box dimension ...
Abel Carvalho, Hans Triebel
wiley +1 more source
Isomorphism theorems for some parabolic initial-boundary value problems in Hörmander spaces
In Hörmander inner product spaces, we investigate initial-boundary value problems for an arbitrary second order parabolic partial differential equation and the Dirichlet or a general first-order boundary conditions.
Los Valerii, Murach Aleksandr
doaj +1 more source
A real variable characterization of Gromov hyperbolicity of flute surfaces [PDF]
23 pages, 1 figure.-- MSC2000 codes: 41A10, 46E35, 46G10.-- ArXiv pre-print available at: http://arxiv.org/abs/0806.0093Previously presented as Communication at International Congress of Mathematicians 2006 (ICM2006, Madrid, Spain, Aug 22-30, 2006 ...
Portilla, Ana +2 more
core +2 more sources
A sharpness result for powers of Besov functions
A recent result of Kateb asserts that f∈Bp,qs(ℝn) implies |f|μ∈Bp,qs(ℝn) as soon as the following three conditions hold: (1) 0≺s≺μ + (1/p), (2) f is bounded, (3) μ≻1. By means of counterexamples, we prove that those conditions are optimal.
Gérard Bourdaud, Jürgen Appell
wiley +1 more source
Hardy–Adams Inequalities on ℍ2 × ℝn-2
Let ℍ2{\mathbb{H}^{2}} be the hyperbolic space of dimension 2. Denote by Mn=ℍ2×ℝn-2{M^{n}=\mathbb{H}^{2}\times\mathbb{R}^{n-2}} the product manifold of ℍ2{\mathbb{H}^{2}} and ℝn-2(n≥3){\mathbb{R}^{n-2}(n\geq 3)}.
Ma Xing, Wang Xumin, Yang Qiaohua
doaj +1 more source
A Note on Div-Curl Lemma [PDF]
2000 Mathematics Subject Classification: 42B30, 46E35, 35B65.We prove two results concerning the div-curl lemma without assuming any sort of exact cancellation, namely the divergence and curl need not be zero, and $$div(u^−v^→) ∈ H^1(R^d)$$ which include
Gala, Sadek
core

