Change search

Some new results concerning Lorentz sequence spaces and Schur multipliers: characterization of some new Banach spaces of infinite matrices
Luleå University of Technology, Department of Engineering Sciences and Mathematics.
2009 (English)Licentiate thesis, comprehensive summary (Other academic)
Abstract [en]

This Licentiate thesis consists of an introduction and three papers, which deal with some new spaces of infinite matrices and Lorentz sequence spaces.In the introduction we give an overview of the area that serves as a frame for the rest of the thesis. In particular, a short description of Schur multipliers is given.In Paper 1 we prove that the space of all bounded operators on $\ell^2$ is contained in the space of all Schur multipliers on $B_w(\ell^2)$, where $B_w(\ell^2)$ is the space of linear (unbounded) operators on $\ell^2$ which map decreasing sequences from $\ell^2$ into sequences from $\ell^2$.In Paper 2 using a special kind of Schur multipliers and G. Bennett's factorization technique we characterize the upper triangular positive matrices from $B_w(\ell^p)$, $1In Paper 3 we consider the Lorentz spaces$\ell^{p,q}$in the range$1$\|x\|_{p,q}=\left(\sum_{n=1}^\infty (x^*)^q n^{\frac{q}{p}-1}\right)^\frac{1}{q}$is only a quasi-norm. In particular, we derive the optimal constant in the triangle inequality for this quasi-norm, which leads us to consider the following decomposition norm:$\|x\|_{(p,q)}=\inf\{\sum_k \|x^{(k)}\|_{p,q}\},$where the infimum is taken over all finite representations $x=\sum_k x^{(k)}$.

Place, publisher, year, edition, pages
Luleå: Luleå tekniska universitet, 2009. , 10 p.
Series
Licentiate thesis / Luleå University of Technology, ISSN 1402-1757
Mathematics
Identifiers
Local ID: 6cb99e40-3004-11de-bd0f-000ea68e967bISBN: 978-91-86233-37-2OAI: oai:DiVA.org:ltu-18094DiVA: diva2:991100
Note
Godkänd; 2009; 20090423 (ancmar); LICENTIATSEMINARIUM Ämnesområde: Matematik/Mathematics Examinator: Professor Lars-Erik Persson, Luleå tekniska universitet Tid: Onsdag den 3 juni 2009 kl 10.15 Plats: D 2214, Luleå tekniska universitetAvailable from: 2016-09-29 Created: 2016-09-29Bibliographically approved

Open Access in DiVA

File information
File name FULLTEXT01.pdfFile size 788 kBChecksum SHA-512
Type fulltextMimetype application/pdf

Search in DiVA

By author/editor
Marcoci, Anca-Nicoleta
By organisation
Department of Engineering Sciences and Mathematics