{ "id": "1906.04514", "version": "v1", "published": "2019-06-11T12:10:45.000Z", "updated": "2019-06-11T12:10:45.000Z", "title": "Simultaneously preperiodic integers for quadratic polynomials", "authors": [ "Valentin Huguin" ], "comment": "13 pages, 6 figures", "categories": [ "math.DS" ], "abstract": "In this article, we study the set of parameters $c \\in \\mathbb{C}$ for which two given complex numbers $a$ and $b$ are simultaneously preperiodic for the quadratic polynomial $f_{c}(z) = z^{2} +c$. Combining complex-analytic and arithmetic arguments, Baker and DeMarco showed that this set of parameters is infinite if and only if $a^{2} = b^{2}$. Recently, Buff answered a question of theirs, proving that the set of parameters $c \\in \\mathbb{C}$ for which both $0$ and $1$ are preperiodic for $f_{c}$ is equal to $\\lbrace -2, -1, 0 \\rbrace$. Following his approach, we complete the description of these sets when $a$ and $b$ are two given integers with $\\lvert a \\rvert \\neq \\lvert b \\rvert$.", "revisions": [ { "version": "v1", "updated": "2019-06-11T12:10:45.000Z" } ], "analyses": { "subjects": [ "37P05", "37F45", "37P35" ], "keywords": [ "simultaneously preperiodic integers", "quadratic polynomial", "parameters", "complex numbers", "arithmetic arguments" ], "note": { "typesetting": "TeX", "pages": 13, "language": "en", "license": "arXiv", "status": "editable" } } }