{ "id": "2502.00727", "version": "v1", "published": "2025-02-02T09:17:30.000Z", "updated": "2025-02-02T09:17:30.000Z", "title": "Inner and characteristic functions in polydiscs", "authors": [ "Ramlal Debnath", "Deepak K. Pradhan", "Jaydeb Sarkar" ], "comment": "43 pages", "categories": [ "math.FA", "math.CV", "math.OA" ], "abstract": "Characteristic functions of linear operators are analytic functions that serve as complete unitary invariants. Such functions, as long as they are built in a natural and canonical manner, provide representations of inner functions on a suitable domain and make significant contributions to the development of various theories in Hilbert function spaces. In this paper, we solve this problem in polydiscs. In particular, we present a concrete description of the characteristic functions of tuples of commuting pure contractions and, consequently, provide a description of inner functions on polydiscs.", "revisions": [ { "version": "v1", "updated": "2025-02-02T09:17:30.000Z" } ], "analyses": { "subjects": [ "46J15", "47A15", "30H05", "47A56", "32A35", "30J05" ], "keywords": [ "characteristic functions", "inner functions", "hilbert function spaces", "complete unitary invariants", "analytic functions" ], "note": { "typesetting": "TeX", "pages": 43, "language": "en", "license": "arXiv", "status": "editable" } } }