{ "id": "2203.01301", "version": "v1", "published": "2022-03-02T18:34:41.000Z", "updated": "2022-03-02T18:34:41.000Z", "title": "Frames of iterations and vector-valued model spaces", "authors": [ "Carlos Cabrelli", "Ursula Molter", "Daniel Suárez" ], "comment": "21 pages", "categories": [ "math.FA", "math.CA" ], "abstract": "Let T be a bounded operator on a Hilbert space H, and F = {f_j: j in J} an at most countable set of vectors in H. In this note, we characterize the pairs {T, F} such that {T^n f: f in F, n in I} form a frame of H, for the cases of I = N_0 and I = Z. The characterization for unilateral iterations gives a similarity with the compression of the shift acting on model spaces of the Hardy space of analytic functions defined on the unit disk with values in $l^2(J). This generalizes recent work for iterations of a single function. In the case of bilateral iterations, the characterization is by the bilateral shift acting on doubly invariant subspaces of L^2(T,l^2(J)). Furthermore, we characterize the frames of iterations for vector-valued model operators when J is finite in terms of Toeplitz and multiplication operators in the unilateral and bilateral case, respectively. Finally, we study the problem of finding the minimal number of orbits that produce a frame in this context.", "revisions": [ { "version": "v1", "updated": "2022-03-02T18:34:41.000Z" } ], "analyses": { "keywords": [ "vector-valued model spaces", "unilateral iterations", "shift acting", "hardy space", "analytic functions" ], "note": { "typesetting": "TeX", "pages": 21, "language": "en", "license": "arXiv", "status": "editable" } } }