Sökning: "generalized Fourier transform"
Visar resultat 1 - 5 av 10 avhandlingar innehållade orden generalized Fourier transform.
1. Some new Fourier multiplier results of Lizorkin and Hörmander types
Sammanfattning : This PhD Thesis is devoted to the study of Fourier series and Fourier transform multipliers and it contains four papers (papers A - D) together with an introduction, which put these papers into a general frame. This extensive introduction can also be seen as an independent description of this important area including the historical development and the most important results. LÄS MER
2. Design of High Performance Computing Software for Genericity and Variability
Sammanfattning : Computer simulations have emerged as a cost efficient complement to laboratory experiments, as computers have become increasingly powerful. The aim of the present work is to explore the ideas of some state of the art software development practices, and ways in which these can be useful for developing high performance research codes. LÄS MER
3. Titchmarsh-Weyl M-function asymptotics and some results in the inverse spectral theory for vector-valued Sturm-Liouville equations and a certain higher order ordinary differential equation
Sammanfattning : This discourse is constituted by two separate reprots, where the first one offers an elementary deduction of the leading order term asymptotics for the Titchmarsh-Weyl M-function corresponding to a vector-valued Sturm-Liouville equation of the form -(PU')'+QU=zu, xin[0,b), with P^{-1},W,Q being hermitean with locally integrable entries; and under some additional conditions on P^{-1} and W. In the special case of P=W=I, we give some further asymptotic results for the same M-function. LÄS MER
4. Summability of Fourier transforms of functions from Lorentz spaces
Sammanfattning : This PhD thesis is devoted to the study of relations between integrability properties of functions and summability properties of its Fourier coefficients and transforms. The relations are given in terms of generalized weighted Lorentz norms, where the weights have some additional growth properties. LÄS MER
5. Some new Lizorkin multiplier theorems for Fourier series and transforms
Sammanfattning : This Licentiate Thesis is devoted to the study of Fourier series and Fourier transform multipliers and contains three papers (papers A - C) together with an introduction, which put these papers into a general frame. In paper A a generalization of the Lizorkin theorem on Fourier multipliers is proved. LÄS MER