{ "id": "2411.11201", "version": "v1", "published": "2024-11-17T23:34:59.000Z", "updated": "2024-11-17T23:34:59.000Z", "title": "An Infinite Family of Artin-Schreier Curves with Minimal a-number", "authors": [ "Iris Y. Shi" ], "categories": [ "math.NT", "math.AG" ], "abstract": "Let $p$ be an odd prime and $k$ be an algebraically closed field with characteristic $p$. Booher and Cais showed that the $a$-number of a $\\mathbb Z/p \\mathbb Z$-Galois cover of curves $\\phi: Y \\to X$ must be greater than a lower bound determined by the ramification of $\\phi$. In this paper, we provide evidence that the lower bound is optimal by finding examples of Artin-Schreier curves that have $a$-number equal to its lower bound for all $p$. Furthermore we use formal patching to generate infinite families of Artin-Schreier curves with $a$-number equal to the lower bound in any characteristic.", "revisions": [ { "version": "v1", "updated": "2024-11-17T23:34:59.000Z" } ], "analyses": { "keywords": [ "artin-schreier curves", "infinite family", "lower bound", "minimal a-number", "number equal" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable" } } }