{ "id": "1908.03555", "version": "v1", "published": "2019-08-09T17:53:17.000Z", "updated": "2019-08-09T17:53:17.000Z", "title": "The angle along a curve and range-kernel complementarity", "authors": [ "Dimosthenis Drivaliaris", "Nikos Yannakakis" ], "categories": [ "math.FA", "math.SP" ], "abstract": "In this paper, we define the angle of a bounded linear operator $A$ along an unbounded path emanating from the origin and use it to characterize range-kernel complementarity. In particular we show that if $0$ faces the unbounded component of the resolvent set, then $X=R(A)\\oplus N(A)$ if and only if $R(A)$ is closed and some angle of $A$ is less than $\\pi$.", "revisions": [ { "version": "v1", "updated": "2019-08-09T17:53:17.000Z" } ], "analyses": { "subjects": [ "47A10", "47A15" ], "keywords": [ "bounded linear operator", "characterize range-kernel complementarity", "resolvent set", "unbounded path", "unbounded component" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable" } } }