acb_theta_g2_chi5
Synopsis
#include <flint/acb_theta.h>void acb_theta_g2_chi5(acb_t res, acb_srcptr th, slong prec)sourceSets res to \chi_5 = - 2^{-6} \prod_{(a,b)\text{ even}} \theta_{a,b}(0, \tau), given the 16 theta constants th. \chi_5 is a Siegel cusp form with character [CFG2019], and \chi_5^2 = \chi_{10}.
References#
- [CFG2019] F. Cléry, C. Faber, and G. van der Geer. "Covariants of binary sextics and modular forms of degree 2 with character", Math. Comp. 88 (2019), 2423–2441. https://doi.org/10.1090/mcom/3412
Cite this page
The FLINT team, “acb_theta_g2_chi5 (acb_theta.h),” FLINT: Fast Library for Number Theory, documentation, version 3.7.0-dev, 2026. https://flintlib.org/doc/acb_theta/acb_theta_g2_chi5.html (generated 2026-10-20).
@misc{flint-doc-acb-theta-acb-theta-g2-chi5,
author = {{The FLINT team}},
title = {{acb\_theta\_g2\_chi5 (acb\_theta.h)}},
howpublished = {FLINT: Fast Library for Number Theory, documentation, version 3.7.0-dev},
year = {2026},
url = {https://flintlib.org/doc/acb_theta/acb_theta_g2_chi5.html},
note = {Generated 2026-10-20}
}