{ "id": "2106.11205", "version": "v1", "published": "2021-06-21T15:45:05.000Z", "updated": "2021-06-21T15:45:05.000Z", "title": "Closedness of the orbit-closed $C$-numerical range and submajorization", "authors": [ "Jireh Loreaux", "Sasmita Patnaik" ], "comment": "19 pages", "categories": [ "math.FA" ], "abstract": "For a positive trace-class operator $C$ and a bounded operator $A$, we provide an explicit description of the closure of the orbit-closed $C$-numerical range of $A$ in terms of those operators submajorized by $C$ and the essential numerical range of $A$. This generalizes and subsumes recent work of Chan, Li and Poon for the $k$-numerical range, as well as some of our own previous work on the orbit-closed $C$-numerical range.", "revisions": [ { "version": "v1", "updated": "2021-06-21T15:45:05.000Z" } ], "analyses": { "subjects": [ "47A12", "47B15", "52A10", "52A40", "26D15" ], "keywords": [ "closedness", "submajorization", "positive trace-class operator", "essential numerical range", "explicit description" ], "note": { "typesetting": "TeX", "pages": 19, "language": "en", "license": "arXiv", "status": "editable" } } }