We approach uncertainty principles of Cowling-Price-Heis-enberg-type as a variational principle on modulation spaces. In our discussion we are naturally led to compact localization operators with symbols in The optimal constant these is the smallest eigenvalue inverse operator. Euler-Lagrange equations for associated functional provide eigenfunctions operators. As by-product proofs derive gener...

We construct an orthonormal basis for the family of bi-variate α-modulation spaces. The construction is based on local trigonometric bases, and the basis elements are closely related to so-called brushlets. As an application, we show that m-term nonlinear approximationwith the system in an α-modulation space can be completely characterized.

Let 1 < p, q < ∞ and s, r ∈ R. It is proved that any function in the amalgam space W (H p′(R ), l∞), where p ′ is the conjugate exponent to p and H p′(R ) is the Bessel potential space, defines a bounded pointwise multiplication operator in the modulation space M p,q(R ), whenever r > |s|+ d.

This is a literal reproduction of the 1983 report [55] by Hans G. Feichtinger, with only the obvious typos being corrected, one additional section and minor extra footnotes. Only few symbols have been changed to more standard ones, e.g. for the translation operator (which was L y , following Hans Reiter) has been replaced by T y , and instead of K(G) we write C c (G) now. We hope that by adding...

'Space and place are central to the strategies and meaning of protest’ (p. xi) reads the opening sentence of Katrina Navickas's latest study, Protest and the Politics of Space and Place 1789–1848. Written, in part, as a response to the 'spatial turn' in History, Navickas makes a cogent and persuasive argument for attending to the importance of the particularities of 'place' rather than the abst...

The aim of this paper is to establish a few qualitative uncertainty principles for the windowed Opdam–Cherednik transform on weighted modulation spaces associated with transform. In particular, we obtain Cowling–Price's, Hardy's and Morgan's spaces. proofs results are based versions Phragmén–Lindlöf type result several complex variables properties Gaussian kernel Jacobi–Cherednik operator.