@inbook{a6548ca9958f46d4a3b35f67fbcf1e92,
title = "Curve equations from expansions of 1-forms at a nonrational point",
abstract = "We exhibit an algorithm to compute equations of an algebraic curve over a computable characteristic 0 field from the power series expansions of its regular 1-forms at a nonrational point of the curve, extending a 2005 algorithm of Baker, Gonz\textbackslash{}'alez-Jim\textbackslash{}'enez, Gonz\textbackslash{}'alez, and Poonen for expansions at a rational point. If the curve is hyperelliptic, the equations present it as an explicit double cover of a smooth plane conic, or as a double cover of the projective line when possible. If the curve is nonhyperelliptic, the equations cut out the canonical model. The algorithm has been used to compute equations over \$\textbackslash{}mathbb\{Q\}\$ for many hyperelliptic modular curves without a rational cusp in the L-functions and Modular Forms Database.",
keywords = "math.NT, 14Q05 (Primary) 11G18, 14G35 (Secondary)",
author = "\{van Bommel\}, Raymond and Edgar Costa and Bjorn Poonen and Padmavathi Srinivasan",
note = "10 pages, comments welcome",
year = "2025",
month = aug,
day = "6",
doi = "10.48550/arXiv.2506.14026",
language = "English",
series = "Contemporary Mathematics",
publisher = "American Mathematical Society",
booktitle = "Contemporary Mathematics",
address = "United States",
}