{ "id": "2402.05503", "version": "v1", "published": "2024-02-08T09:21:29.000Z", "updated": "2024-02-08T09:21:29.000Z", "title": "On the type of ill-posedness of generalized Hilbert matrices and related operators", "authors": [ "Stefan Kindermann" ], "categories": [ "math.FA" ], "abstract": "We consider infinite-dimensional generalized Hilbert matrices of the form $H_{i,j} = \\frac{d_i d_j}{x_i + x_j}$, where $d_i$ are nonnegative weights and $x_i$ are pairwise disjoint positive numbers. We state sufficient and, for monotonically rearrangeable $x_i$, also necessary conditions for $d_i$, $x_i$ such that the induced operator from $\\ell^2 \\to \\ell^2$ and related operators are well-defined, bounded, or compact. Furthermore, we give conditions, when this operator is injective and ill-posed.", "revisions": [ { "version": "v1", "updated": "2024-02-08T09:21:29.000Z" } ], "analyses": { "keywords": [ "related operators", "ill-posedness", "infinite-dimensional generalized hilbert matrices", "pairwise disjoint positive numbers", "state sufficient" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable" } } }