{ "id": "2309.10303", "version": "v1", "published": "2023-09-19T04:10:10.000Z", "updated": "2023-09-19T04:10:10.000Z", "title": "Locally nilpotent polynomials over $\\mathbb{Z}$", "authors": [ "Sayak Sengupta" ], "comment": "17 pages. Few edits throughout the entire paper and one newly added subsection. To appear in INTEGERS. arXiv admin note: substantial text overlap with arXiv:2211.06760", "categories": [ "math.NT", "math.DS" ], "abstract": "For a polynomial $u=u(x)$ in $\\mathbb{Z}[x]$ and $r\\in\\mathbb{Z}$, we consider the orbit of $u$ at $r$ denoted and defined by $\\mathcal{O}_u(r):=\\{u(r),u(u(r)),\\ldots\\}$. We ask two questions here: (i) what are the polynomials $u$ for which $0\\in \\mathcal{O}_u(r)$, and (ii) what are the polynomials for which $0\\not\\in \\mathcal{O}_u(r)$ but, modulo every prime $p$, $0\\in \\mathcal{O}_u(r)$? In this paper, we give a complete classification of the polynomials for which (ii) holds for a given $r$. We also present some results for some special values of $r$ where (i) can be answered.", "revisions": [ { "version": "v1", "updated": "2023-09-19T04:10:10.000Z" } ], "analyses": { "subjects": [ "11A41", "37P05", "11A05", "11A07", "37P25" ], "keywords": [ "locally nilpotent polynomials", "complete classification", "special values" ], "note": { "typesetting": "TeX", "pages": 17, "language": "en", "license": "arXiv", "status": "editable" } } }