Let and be bilinear forms
and suppose that and are bounded in with bounds and . Then
where the series
is absolutely convergent, is called the faltung of and . is bounded in , and its bound does not exceed .
References
Hardy, G. H.; Littlewood, J. E.; and Pólya, G. Inequalities, 2nd ed. Cambridge,
England: Cambridge University Press, pp. 210-211, 1988.
© 1996-9 Eric W. Weisstein
1999-05-26