English

Modular Forms and Numerical Explorations of Rational Approximations to $\zeta(3)$

Number Theory 2026-05-04 v1 Numerical Analysis Numerical Analysis

Abstract

We revisit Beukers' modular-form proof of the irrationality of ζ(3)\zeta(3) from the point of view of the auxiliary weight two modular form. For the Fricke group Γ0(6)\Gamma_0(6)^\star, we show that Beukers' choice is not isolated: it belongs to a one-parameter affine family. These approximations have the same exponential decay as the classical Ap\'ery approximations and satisfy the same denominator-growth estimate needed in Beukers' irrationality argument. We then apply the same construction to several other genus-zero Fricke groups.

Keywords

Cite

@article{arxiv.2605.00673,
  title  = {Modular Forms and Numerical Explorations of Rational Approximations to $\zeta(3)$},
  author = {Cynthia Bortolotto and Lucas Oliveira},
  journal= {arXiv preprint arXiv:2605.00673},
  year   = {2026}
}