{ "id": "2406.19916", "version": "v1", "published": "2024-06-28T13:39:59.000Z", "updated": "2024-06-28T13:39:59.000Z", "title": "The truncated multidimensional moment problem: canonical solutions", "authors": [ "Sergey M. Zagorodnyuk" ], "comment": "25 pages", "categories": [ "math.CA" ], "abstract": "For the truncated multidimensional moment problem we introduce a notion of a canonical solution. Namely, canonical solutions are those solutions which are generated by commuting self-adjoint extensions inside the associated Hilbert space. It is constructed a 1-1 correspondence between canonical solutions and flat extensions of the given moments (both sets may be empty). In the case of the two-dimensional moment problem (with triangular truncations) a search for canonical solutions leads to an algebraic system of equations. A notion of the index $i_s$ of nonself-adjointness for a set of prescribed moments is introduced. The case $i_s=0$ corresponds to flatness. In the case $i_s=1$ we get explicit necessary and sufficient conditions for the existence of canonical solutions. These conditions are valid for arbitrary sizes of truncations. In the case $i_s=2$ we get either explicit conditions for the existence of canonical solutions or a single quadratic equation with several unknowns. Numerical examples are provided.", "revisions": [ { "version": "v1", "updated": "2024-06-28T13:39:59.000Z" } ], "analyses": { "subjects": [ "44A60" ], "keywords": [ "truncated multidimensional moment problem", "canonical solution", "conditions", "two-dimensional moment problem", "commuting self-adjoint extensions inside" ], "note": { "typesetting": "TeX", "pages": 25, "language": "en", "license": "arXiv", "status": "editable" } } }