Sökning: "weighted function spaces"

Visar resultat 1 - 5 av 27 avhandlingar innehållade orden weighted function spaces.

1. 1. The Weighted Space Odyssey

   Författare :Martin Křepela; Sorina Barza; Gord Sinnamon; Karlstads universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; integral operators; supremal operators; weights; weighted function spaces; Lorentz spaces; Lebesgue spaces; convolution; Hardy inequality; multilinear operators; nonincreasing rearrangement; Matematik; Mathematics;

   Sammanfattning : The common topic of this thesis is boundedness of integral and supremal operators between weighted function spaces.The first type of results are characterizations of boundedness of a convolution-type operator between general weighted Lorentz spaces. LÄS MER

3. 2. Studies of some Operators of Harmonic Analysis in certain Function Spaces with Applications to PDEs

   Författare :Staffan Lundberg; Norway Narvik UiT The Arctic University of Norway Department of Computer Science and Computational Engineering Faculty of Science and Technology; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Operators; Hardy Operators; Potential Operators; Singular Operators; Function Spaces; Morrey Spaces; H¨older Spaces; Partial Differential Equations; Inequalities; Hardy Type Inequalities; Weights; Applications; Matematik; Mathematics;

   Sammanfattning : The study in this PhD thesis aims at development of certain mathematical methods used in applications, in particular, in the study of regularity properties of solutions in various mathematical models described by Partial Differential Equations (PDEs). To this end, we study various operators of harmonic analysis in certain function spaces, since solutions to many PDEs may be expressed in terms of such operators. LÄS MER

4. 3. Forever Young : Convolution Inequalities in Weighted Lorentz-type Spaces

   Författare :Martin Křepela; Sorina Barza; Javier Soria; Karlstads universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Convolution; Young inequality; Lorentz spaces; weights; rearrangement-invariant spaces; Matematik; Mathematics;

   Sammanfattning : This thesis is devoted to an investigation of boundedness of a general convolution operator between certain weighted Lorentz-type spaces with the aim of proving analogues of the Young convolution inequality for these spaces.Necessary and sufficient conditions on the kernel function are given, for which the convolution operator with the fixed kernel is bounded between a certain domain space and the weighted Lorentz space of type Gamma. LÄS MER

5. 4. Interpolation of Hilbert spaces

   Författare :Yacin Ameur; Frank Hansen; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Mathematics; Interpolation; Hilbert space; K-functional; K-monotonicity; Calderon couple; Pick function; matrix monotone function; K_2-functional; Löwner s and Donoghue s theorems.; MATEMATIK; MATHEMATICS; MATEMATIK; Mathematics; Matematik;

   Sammanfattning : (i) We prove that intermediate Banach spaces A, B with respect to arbitrary Hilbert couples H, K are exact interpolation iff they are exact K-monotonic, i.e. the condition f0∊A and the inequality K(t,g0;K)≤K(t,f0;H), t>0 imply g0∊B and ||g0||B≤||f0||A (K is Peetre's K-functional). LÄS MER

7. 5. Function spaces and rational inner functions on polydiscs

   Författare :Linus Bergqvist; Alan Sola; Jan-Fredrik Olsen; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Complex variables; Hilbert spaces;

   Sammanfattning : In this thesis we consider problems related to rational inner functionsand several different Hilbert spaces on the unit polydisc. In the general introduction the functions and the function spaces we will be interested in are introduced, and in particular we point outproblems and phenomena that occur in higher dimensions and are notpresent for one variable functions. LÄS MER