Hardy-Littlewood inequalities and Fourier multipliers on SU(2)
arXiv:1403.1731
Abstract
In this paper we prove a noncommutative version of Hardy-Littlewood inequalities relating a function and its Fourier coefficients on the group . As a consequence, we use it to obtain lower bounds for the norms of Fourier multipliers on the group , for . In addition, we give upper bounds of a similar form, analogous to the known results on the torus, but now in the noncommutative setting of .
To appear in Studia Math