Results 31 to 40 of about 161 (110)
Modulation spaces Mp,q for 0 < p, q?8
Journal 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
Journal 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
Analyze Second‐Order PDEs Using the Volterra–Fredholm Integral Equation
Journal of Function Spaces, Volume 2025, Issue 1, 2025.In this study, we propose a novel approach to address a particular second‐order partial differential equation along with its boundary value conditions (SPDEs). In this process, we transfer the SPDEs problem into Volterra–Fredholm integral equation (VFIE), and we perform the Tau method bases on orthogonal Legendre polynomials directly, for solution of ...
Choonkil Park +2 more
wiley +1 more source
Sobolev type inequalities in ultrasymmetric spaces with applications to Orlicz‐Sobolev embeddings
Journal 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
Journal 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
Sobolev extension in a simple case
Advanced Nonlinear StudiesIn this paper, we establish the existence of a bounded, linear extension operator T:L2,p(E)→L2,p(R2) $T :{L}^{2,p}\left(E\right)\to {L}^{2,p}\left({\mathbb{R}}^{2}\right)$ when 1 < p < 2 and E is a finite subset of R2 ${\mathbb{R}}^{2}$ contained in a ...
Drake Marjorie +3 more
doaj +1 more source
Box dimension, oscillation and smoothness in function spaces
Journal of Function Spaces, Volume 3, Issue 3, Page 287-320, 2005., 2005 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
Open Mathematics, 2017 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 sharpness result for powers of Besov functions
Journal of Function Spaces, Volume 2, Issue 3, Page 267-277, 2004., 2004 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
Advanced Nonlinear Studies, 2021 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