On the Extension of Bounded Holomorphic Maps from Gleason Parts of the Maximal Ideal Space of $H^\infty $

Brudnyi, Alexander

Canadian mathematical bulletin, Tome 67 (2024) no. 3, pp. 624-632

Résumé

Let $H^\infty $ be the algebra of bounded holomorphic functions on the open unit disk, and let $\mathfrak M$ be its maximal ideal space. Let $\mathfrak M_a$ be the union of nontrivial Gleason parts (analytic disks) of $\mathfrak M$. In this paper, we study the problem of extensions of bounded Banach-valued holomorphic functions and holomorphic maps with values in Oka manifolds from Gleason parts of $\mathfrak M_a\setminus \mathbb {D}$. The resulting extensions satisfy the uniform boundedness principle in the sense that their norms are bounded by constants that do not depend on the choice of the Gleason part. The results extend fundamental results of D. Suárez on the characterization of the algebra of restrictions of Gelfand transforms of functions in $H^\infty $ to Gleason parts of $ \mathfrak M_a\setminus \mathbb {D}$. The proofs utilize our recent advances on $\bar \partial $-equations on quasi-interpolating sets and Runge-type approximations.

Détail

DOI : 10.4153/S0008439524000018

Mots-clés : Bounded holomorphic function, maximal ideal space, Gleason part, Oka manifold