TY - JOUR
T1 - General Optimal Polynomial Approximants, Stabilization, and Projections of Unity
AU - Felder , Christopher
JO - Analysis in Theory and Applications
VL - 4
SP - 309
EP - 329
PY - 2023
DA - 2023/12
SN - 39
DO - http://doi.org/10.4208/ata.OA-2020-0047
UR - https://global-sci.org/intro/article_detail/ata/22300.html
KW - Optimal polynomial approximants, inner functions.
AB - <p style="text-align: justify;">In various Hilbert spaces of analytic functions on the unit disk, we characterize when a function has optimal polynomial approximants given by truncations of
a single power series or, equivalently, when the approximants stabilize. We also introduce a generalized notion of optimal approximant and use this to explicitly compute
orthogonal projections of 1 onto certain shift invariant subspaces.</p>