{ "id": "2208.09890", "version": "v1", "published": "2022-08-21T14:24:05.000Z", "updated": "2022-08-21T14:24:05.000Z", "title": "Counting points on smooth plane quartics", "authors": [ "Edgar Costa", "David Harvey", "Andrew V. Sutherland" ], "comment": "32 pages", "categories": [ "math.NT" ], "abstract": "We present efficient algorithms for counting points on a smooth plane quartic curve $X$ modulo a prime $p$. We address both the case where $X$ is defined over $\\mathbb F_p$ and the case where $X$ is defined over $\\mathbb Q$ and $p$ is a prime of good reduction. We consider two approaches for computing $\\#X(\\mathbb F_p)$, one which runs in $O(p\\log p\\log\\log p)$ time using $O(\\log p)$ space and one which runs in $O(p^{1/2}\\log^2\\!p)$ time using $O(p^{1/2}\\log p)$ space. Both approaches yield algorithms that are faster in practice than existing methods. We also present average polynomial-time algorithms for $X/\\mathbb Q$ that compute $\\#X(\\mathbb F_p)$ for good primes $p\\le N$ in $O(N\\log^3\\! N)$ time using $O(N)$ space. These are the first practical implementations of average polynomial-time algorithms for curves that are not cyclic covers of $\\mathbb P^1$, which in combination with previous results addresses all curves of genus $g\\le 3$. Our algorithms also compute Cartier-Manin/Hasse-Witt matrices that may be of independent interest.", "revisions": [ { "version": "v1", "updated": "2022-08-21T14:24:05.000Z" } ], "analyses": { "subjects": [ "11G40", "14G10", "14H25", "11Y16" ], "keywords": [ "counting points", "average polynomial-time algorithms", "smooth plane quartic curve", "approaches yield algorithms", "efficient algorithms" ], "note": { "typesetting": "TeX", "pages": 32, "language": "en", "license": "arXiv", "status": "editable" } } }