English

Ramanujan--Fine integrals for level 10

Number Theory 2025-03-25 v2

Abstract

We investigate the question of when an eta quotient is a derivative of a formal power series with integer coefficients and present an analysis in the case of level 10. As a consequence, we establish and classify an infinite number of integral evaluations such as 0e2π/10qj=1(1qj)3(1q10j)8(1q5j)7dq=14(10451). \int_0^{e^{-2\pi/\sqrt{10}}} q\prod_{j=1}^\infty \frac{(1-q^j)^3(1-q^{10j})^8}{(1-q^{5j})^7} \text{d} q = \frac14\left(\sqrt{10-4\sqrt{5}}-1\right). We describe how the results were found and give reasons for why it is reasonable to conjecture that the list is complete for level 10.

Cite

@article{arxiv.2410.19186,
  title  = {Ramanujan--Fine integrals for level 10},
  author = {Shaun Cooper and Timothy Huber and Jeffery Opoku},
  journal= {arXiv preprint arXiv:2410.19186},
  year   = {2025}
}
R2 v1 2026-06-28T19:34:57.129Z