Functions with small and large spectra as (non)extreme points

Description:  Let $\Lambda$ be a subset of $\mathbb Z_+:=\{0,1,2,\dots\}$, and let $H^\infty(\Lambda)$ denote the space of bounded analytic functions $f$ on the unit disk whose coefficients $\widehat f(k)$ vanish for $k\notin\La$. Assuming that either $\Lambda$ or $\mathbb Z_+\setminus\Lambda$ is finite, we determine the extreme points of the unit ball in $H^\infty(\Lambda)$. Date:  2021-12-10 Start Time:   14:30 Speaker:  Konstantin Dyakonov (ICREA & Universitat de Barcelona, Spain) Institution:  ICREA & Universitat de Barcelona, Spain Place:  Sala 5.5 Research Groups: -Analysis See more:   <Main>