Multi-orbital Frames Through Model Spaces

CABRELLI, CARLOS; MOLTER, URSULA; SUÁREZ, DANIEL

COMPLEX ANALYSIS AND OPERATOR THEORY

BIRKHAUSER VERLAG AG

Año: 2021 vol. 15

1661-8254

We characterize the normal operators $A$ on $ell^2$ and the elements$a^i in ell^2$, with $1le ile m$, such that the sequence$${ A^n a^1 , ldots , A^n a^m }_{nge 0}$$is a frame.The characterization makes strong use of the pseudo-hyperbolic metric of $disc$ and is given in termsof the backward shift-invariant subspaces of $H^2(disc)$ associated to finite productsof interpolating Blaschke products.}