Results 21 to 30 of about 144 (124)
A criterion of weak compactness for operators on subspaces of Orlicz spaces
Journal of Function Spaces, Volume 6, Issue 3, Page 277-292, 2008., 2008 We give a criterion of weak compactness for the operators on the Morse‐Transue space MΨ, the subspace of the Orlicz space LΨ generated by L∞.
Pascal Lefèvre +4 more
wiley +1 more source
Weighted CBMO estimates for commutators of matrix Hausdorff operator on the Heisenberg group
Open Mathematics, 2020 In this article, we study the commutators of Hausdorff operators and establish their boundedness on the weighted Herz spaces in the setting of the Heisenberg group.
Ajaib Amna, Hussain Amjad
doaj +1 more source
On the trace space of a Sobolev space with a radial weight
Journal of Function Spaces, Volume 6, Issue 3, Page 259-276, 2008., 2008 Our concern in this paper lies with trace spaces for weighted Sobolev spaces, when the weight is a power of the distance to a point at the boundary. For a large range of powers we give a full description of the trace space.
Helmut Abels +3 more
wiley +1 more source
Extremal points without compactness in L1(μ)
Journal of Function Spaces, Volume 5, Issue 2, Page 199-211, 2007., 2007 We investigate the existence of extremal points and the Krein‐MIlman representation A=co̅ExtA of bounded convex subsets of L1(μ) which are only closed with respect to the topology of μ‐a.e. convergence.
Anna Martellotti, Jürgen Appell
wiley +1 more source
A note on maximal operator on ℓ{pn} and Lp(x)(ℝ)
Journal of Function Spaces, Volume 5, Issue 1, Page 49-88, 2007., 2007 We consider a discrete analogue of Hardy‐Littlewood maximal operator on the generalized Lebesque space ℓ{pn} of sequences defined on ℤ. It is known a necessary and sufficient condition P which guarantees an existence of a real number p > 1 such that the norms in the space ℓ{pn} and in the classical space ℓp are equivalent.
Aleš Nekvinda, Pankaj Jain
wiley +1 more source
Weighted norm inequalities and indices
Journal of Function Spaces, Volume 4, Issue 1, Page 43-71, 2006., 2006 We extend and simplify several classical results on weighted norm inequalities for classical operators acting on rearrangement invariant spaces using the theory of indices. As an application we obtain necessary and sufficient conditions for generalized Hardy type operators to be bounded on ?p(w), ?p,8(w), Gp(w) and Gp,8(w).
Joaquim Martín +2 more
wiley +1 more source
New classes of rearrangement‐invariant spaces appearing in extreme cases of weak interpolation
Journal 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
Non‐equivalent greedy and almost greedy bases in lp
Journal of Function Spaces, Volume 4, Issue 1, Page 25-42, 2006., 2006 For 1 < p < 8 and p ? 2 we construct a family of mutually non‐equivalent greedy bases in lp having the cardinality of the continuum. In fact, no basis from this family is equivalent to a rearranged subsequence of any other basis thereof. We are able to extend this statement to the spaces Lp and H1.
Stephen J. Dilworth +3 more
wiley +1 more source
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
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