English

Zeros of Ramanujan-type Polynomials

Number Theory 2023-06-21 v1

Abstract

Ramanujan's notebooks contain many elegant identities and one of the celebrated identities is a formula for ζ(2k+1)\zeta(2k+1). In 1972, Grosswald gave an extension of the Ramanujan's formula for ζ(2k+1)\zeta(2k+1), which contains a polynomial of degree 2k+22k+2. This polynomial is now well-known as the Ramanujan polynomialR2k+1(z)R_{2k+1}(z), first studied by Gun, Murty, and Rath. Around the same time, Murty, Smith and Wang proved that all the non-real zeros of R2k+1(z)R_{2k+1}(z) lie on the unit circle. Recently, Chourasiya, Jamal, and the first author found a new polynomial while obtaining a Ramanujan-type formula for Dirichlet LL-functions and named it as Ramanujan-type polynomial R2k+1,p(z)R_{2k+1,p}(z). In the same paper, they conjectured that all the non-real zeros of R2k+1,p(z)R_{2k+1,p}(z) lie on the circle z=1/p|z|=1/p. The main goal of this paper is to present a proof of this conjecture.

Keywords

Cite

@article{arxiv.2306.10283,
  title  = {Zeros of Ramanujan-type Polynomials},
  author = {Bibekananda Maji and Tithi Sarkar},
  journal= {arXiv preprint arXiv:2306.10283},
  year   = {2023}
}

Comments

14 pages, comments are welcome!

R2 v1 2026-06-28T11:07:50.299Z