Distribution Theory based on Time-Frequency AnalysisHans G. Feichtinger given at OEMG Conference 2013 (23.09.13) id: 2530 length: min status: type: LINK-Presentation: https://nuhagphp.univie.ac.at/dateien/talks/2530_FeiOEMG13.pdf ABSTRACT: The goal of this presentation is to give a short summary of basic facts concerning time-frequency analysis, in particular Gabor analysis. It provides the possibility of expanding functions (and in fact tempered distributions) as unconditionally convergent double sums of time-frequency shifted atoms, typically some non-zero Schwartz function, like the Gauss function. For the analysis of the various mappings (e.g. from the signal to the sampled short-time Fourier transform) various requirements have to be made, and a certain Segal algebra $S_0(R^d)$ turned out to be a versatile tool in this context. We will indicate that this space is also quite useful for the context of classical Fourier analysis. Furthermore we point out how it can be used to establish a so-called Banach Gelfand triple, consisting of the space $S_0(R^d)$, the Hilbert space $L^2(R^d) and the dual space, each one contained in the next one. Among others one can view the Fourier transform as a unitary Banach Gelfand triple automorphism of this triple, mapping pure frequencies into Dirac measures (and being uniquely determined by this property). OLD VERSION: Gabor Analysis with general lattices We plan to describe some progress concerning Gabor Analysis, using non-separable lattices. This topic is specially interesting for the case of 2D signals (applications in image processing), because then 4-dimensional lattices occur. |