

Author: Sugimoto Mitsuru
Publisher: Taylor & Francis Ltd
ISSN: 1065-2469
Source: Integral Transforms and Special Functions, Vol.22, Iss.4-5, 2011-04, pp. : 351-358
Disclaimer: Any content in publications that violate the sovereignty, the constitution or regulations of the PRC is not accepted or approved by CNPIEC.
Abstract
Let F(f) be the composition of functions F and f. We consider the question 'If f belongs to some function space, does F(f) belong to the same space again?'. The answers to this question for the Sobolev space and the Besov space are well known by virtue of the theory of paradifferential operators by Bony [Calcul symbolique et propagation des singularites pour les equations aux derivees partielles non lineaires, Ann. Sci. Ecole Norm. Sup. (4) 14 (1981), pp. 209-246] and Meyer [Remarques sur un theoreme de J.-M. Bony, Proceedings of the Seminar on Harmonic Analysis (Pisa, 1980), Rend. Circ. Mat. Palermo Vol. 2, Suppl. 1, 1981, pp. 1-20]. This note is a trial to answer this question for the modulation space which is defined by using the short-time Fourier transform, a real variable reformulation of the Bargmann transform. The idea of the modulation space is to consider the space variable and the variable of its Fourier transform simultaneously to measure the decaying and regularity property. We give some partial answers to this question for this relatively new function space. We also give a less restrictive answer for the Wiener amalgam, a variant of the modulation space.
Related content




REMARKS ON QUASI-LINDELÖF SPACES
Bulletin of the Australian Mathematical Society, Vol. 88, Iss. 3, 2013-12 ,pp. :


Remarks on Nonlinear Evolution Equations
By Zhao J.
Journal of Mathematical Analysis and Applications, Vol. 203, Iss. 3, 1996-11 ,pp. :


Remarks on the topology of spatial polygon spaces
Bulletin of the Australian Mathematical Society, Vol. 58, Iss. 3, 1998-12 ,pp. :


Remarks on completeness in spaces of linear operators
Bulletin of the Australian Mathematical Society, Vol. 34, Iss. 1, 1986-08 ,pp. :