papers

Publications (30)

math.NT2024

Hypergeometric -functions in average polynomial time, II

Edgar Costa, Kiran S. Kedlaya, David Roe

For a fixed positive integer , we describe an algorithm for computing, for all primes , the mod- reduction of the trace of Frobenius at of a fixed hypergeomet…

math.NT2020

Rigorous computation of the endomorphism ring of a Jacobian

Edgar Costa, Nicolas Mascot, Jeroen Sijsling +1

We describe several improvements to algorithms for the rigorous computation of the endomorphism ring of the Jacobian of a curve defined over a number field.

math.NT2013

Asymptotic expansions, -values and a new Quantum Modular Form

Edgar Costa, Korneel Debaene, João Guerreiro

In 2010 Zagier introduced the notion of a quantum modular form. One of his first examples was the "strange" function of Kontsevich. Here we produce a new example of a quantu…

math.NT2023

Computing isogeny classes of typical principally polarized abelian surfaces over the rationals

Raymond van Bommel, Shiva Chidambaram, Edgar Costa +1

We describe an efficient algorithm which, given a principally polarized (p.p.) abelian surface over with geometric endomorphism ring equal to , compute…

math.NT2025

Curve equations from expansions of 1-forms at a nonrational point

Raymond van Bommel, Edgar Costa, Bjorn Poonen +1

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…

math.NT2022

Counting points on smooth plane quartics

Edgar Costa, David Harvey, Andrew V. Sutherland

We present efficient algorithms for counting points on a smooth plane quartic curve modulo a prime . We address both the case where is defined over and the…