{ "id": "2301.12816", "version": "v1", "published": "2023-01-30T12:13:00.000Z", "updated": "2023-01-30T12:13:00.000Z", "title": "Specialization of Mordell-Weil ranks of abelian schemes over surfaces to curves", "authors": [ "Timo Keller" ], "comment": "accepted for publication in International Journal of Number Theory", "categories": [ "math.NT", "math.AG" ], "abstract": "Using the Shioda-Tate theorem and an adaptation of Silverman's specialization theorem, we reduce the specialization of Mordell-Weil ranks for abelian varieties over fields finitely generated over infinite finitely generated fields $k$ to the the specialization theorem for N\\'eron-Severi ranks recently proved by Ambrosi in positive characteristic. More precisely, we prove that after a blow-up of the base surface $S$, for all vertical curves $S_x$ of a fibration $S \\to U \\subseteq \\mathbf{P}^1_k$ with $x$ from the complement of a sparse subset of $|U|$, the Mordell-Weil rank of an abelian scheme over $S$ stays the same when restricted to $S_x$.", "revisions": [ { "version": "v1", "updated": "2023-01-30T12:13:00.000Z" } ], "analyses": { "subjects": [ "11G10", "11G05", "11G35" ], "keywords": [ "mordell-weil rank", "abelian scheme", "silvermans specialization theorem", "neron-severi ranks", "base surface" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable" } } }