{ "id": "2407.17352", "version": "v1", "published": "2024-07-24T15:24:22.000Z", "updated": "2024-07-24T15:24:22.000Z", "title": "Invariant subspaces of perturbed backward shift", "authors": [ "Soma Das", "Jaydeb Sarkar" ], "comment": "26 pages", "categories": [ "math.FA", "math.CV", "math.OA" ], "abstract": "We represent closed subspaces of the Hardy space that are invariant under finite-rank perturbations of the backward shift. We apply this to classify almost invariant subspaces of the backward shift and represent closed subspaces that are invariant under a more refined version of nearly invariant subspaces of the backward shift. Kernels of certain perturbed Toeplitz operators are examples of the newly introduced nearly invariant subspaces.", "revisions": [ { "version": "v1", "updated": "2024-07-24T15:24:22.000Z" } ], "analyses": { "subjects": [ "30H10", "47A15", "47B35", "46E22" ], "keywords": [ "invariant subspaces", "perturbed backward shift", "represent closed subspaces", "hardy space", "finite-rank perturbations" ], "note": { "typesetting": "TeX", "pages": 26, "language": "en", "license": "arXiv", "status": "editable" } } }