{ "id": "1807.05624", "version": "v1", "published": "2018-07-15T22:13:48.000Z", "updated": "2018-07-15T22:13:48.000Z", "title": "The conjecture of Ulam on the invariance of measure on Hilbert cube", "authors": [ "Soon-Mo Jung" ], "comment": "14 pages", "categories": [ "math.FA" ], "abstract": "A conjecture of Ulam states that the standard probability measure $\\pi$ on the Hilbert cube $I^\\omega$ is invariant under the induced metric $d_a$ provided the sequence $a = \\{ a_i \\}$ of positive numbers satisfies the condition $\\sum\\limits_{i=1}^\\infty a_i^2 < \\infty$. In this paper, we prove this conjecture in the affirmative. More precisely, we prove that if there exists a surjective $d_a$-isometry $f : E_1 \\to E_2$, where $E_1$ and $E_2$ are Borel subsets of $I^\\omega$, then $\\pi(E_1) = \\pi(E_2)$.", "revisions": [ { "version": "v1", "updated": "2018-07-15T22:13:48.000Z" } ], "analyses": { "subjects": [ "28C10", "28A35", "28A12", "28A75" ], "keywords": [ "hilbert cube", "conjecture", "invariance", "standard probability measure", "ulam states" ], "note": { "typesetting": "TeX", "pages": 14, "language": "en", "license": "arXiv", "status": "editable" } } }