A well known theorem of Nehari asserts on the circle group that bilinear forms in H² can be lifted to linear functionals on H¹. We show that this result can be extended to Hankel forms in infinitely many variables of a certain type. As a corollary we find a new proof that all the norms on the class of Steinhaus series are equivalent.
@article{bwmeta1.element.bwnjournal-article-doi-10_4064-sm176-1-6, author = {Henry Helson}, title = {Hankel forms and sums of random variables}, journal = {Studia Mathematica}, volume = {173}, year = {2006}, pages = {85-92}, zbl = {1108.43003}, language = {en}, url = {http://dml.mathdoc.fr/item/bwmeta1.element.bwnjournal-article-doi-10_4064-sm176-1-6} }
Henry Helson. Hankel forms and sums of random variables. Studia Mathematica, Tome 173 (2006) pp. 85-92. http://gdmltest.u-ga.fr/item/bwmeta1.element.bwnjournal-article-doi-10_4064-sm176-1-6/