scholarly journals Zak transforms and Gabor frames of totally positive functions and exponential B-splines

2014 ◽  
Vol 184 ◽  
pp. 209-237 ◽  
Author(s):  
Tobias Kloos ◽  
Joachim Stöckler
2017 ◽  
Vol 211 (3) ◽  
pp. 1119-1148 ◽  
Author(s):  
Karlheinz Gröchenig ◽  
José Luis Romero ◽  
Joachim Stöckler

2014 ◽  
Vol 60 (1) ◽  
pp. 159-169 ◽  
Author(s):  
Severin Bannert ◽  
Karlheinz Grochenig ◽  
Joachim Stockler

2013 ◽  
Vol 162 (6) ◽  
pp. 1003-1031 ◽  
Author(s):  
Karlheinz Gröchenig ◽  
Joachim Stöckler

2007 ◽  
Vol 200 (1) ◽  
pp. 255-265 ◽  
Author(s):  
Costanza Conti ◽  
Laura Gori ◽  
Francesca Pitolli

2019 ◽  
Vol 33 (3) ◽  
pp. 723-744 ◽  
Author(s):  
Karlheinz Gröchenig ◽  
Philippe Jaming ◽  
Eugenia Malinnikova

AbstractWe study the question under which conditions the zero set of a (cross-) Wigner distribution W(f, g) or a short-time Fourier transform is empty. This is the case when both f and g are generalized Gaussians, but we will construct less obvious examples consisting of exponential functions and their convolutions. The results require elements from the theory of totally positive functions, Bessel functions, and Hurwitz polynomials. The question of zero-free Wigner distributions is also related to Hudson’s theorem for the positivity of the Wigner distribution and to Hardy’s uncertainty principle. We then construct a class of step functions S so that the Wigner distribution $$W(f,\mathbf {1}_{(0,1)})$$ W ( f , 1 ( 0 , 1 ) ) always possesses a zero $$f\in S \cap L^p$$ f ∈ S ∩ L p when $$p<\infty $$ p < ∞ , but may be zero-free for $$f\in S \cap L^\infty $$ f ∈ S ∩ L ∞ . The examples show that the question of zeros of the Wigner distribution may be quite subtle and relate to several branches of analysis.


2015 ◽  
Vol 39 (3) ◽  
pp. 534-544 ◽  
Author(s):  
Ole Christensen ◽  
Hong Oh Kim ◽  
Rae Young Kim
Keyword(s):  

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