1
$\begingroup$

If $B={\prod}_j \varphi_j$ is a Blaschke product (finite or infinite) of Blaschke factors $\varphi_j(w)=\frac{w-\alpha_j}{1-\overline{\alpha_j}w}$ with $|\alpha_j|>1$, is it true that the norm of the Hankel operator (in Hardy spaces on the unit disk) $\Vert H_B\Vert$ is equal to one?

I think I have proved it for a Blaschke factor but I do not see how to generalize it (if it is possible).

Improve this question
$\endgroup$
3
  • $\begingroup$ To produce the double bar needed for typing norms, use \| instead of the uglier ||. $\endgroup$
    – Alex M.
    Commented Oct 12, 2017 at 17:16
  • $\begingroup$ This seems to be the same (or at least very similar) to your question on math.SE: Hankel operator with symbol a Blaschke product. $\endgroup$
    – Martin Sleziak
    Commented Oct 13, 2017 at 5:24
  • $\begingroup$ Humans make mystakes... I am not used to this website. What's your point? $\endgroup$
    – Babyblog
    Commented Oct 13, 2017 at 12:09

0

Reset to default

You must log in to answer this question.