Multiplication and Composition in Weighted Modulation Spaces
  We study the existence of the product of two weighted modulation spaces. For this purpose we discuss two different strategies. The more simple one allows transparent proofs in various situations. However, our second method allows a closer look onto associated norm inequalities under restrictions in the Fourier image. This will give us the opportunity to treat the boundedness of composition operators. 
Maximilian Reich, Winfried Sickel
math.FA