English

On the correlations between character sums of division polynomials under shifts

Number Theory 2025-07-15 v1

Abstract

Let EE be an elliptic curve over the finite field Fp\mathbb{F}_p, and PE(Fp)P \in E(\mathbb{F}_p) be an Fp\mathbb{F}_p-rational point. We study the sums Sχ,P(N,h)=n=1Nχ(ψn(P))χ(ψn+h(P)), S_{\chi,P}(N,h) = \sum_{n=1}^N \chi(\psi_n(P)) \chi(\psi_{n+h}(P)), where ψn(P)\psi_n(P) denotes the nn-th division polynomial evaluated at PP, and χ\chi is a multiplicative character of Fp\mathbb{F}_p^{*}. We estimate Sχ,P(N,h)S_{\chi,P}(N,h) on average over hh over a rather short interval h[1,H]h \in [1, H]. We also obtain a multidimensional generalisation of this result.

Keywords

Cite

@article{arxiv.2507.09271,
  title  = {On the correlations between character sums of division polynomials under shifts},
  author = {Subham Bhakta and Igor E. Shparlinski},
  journal= {arXiv preprint arXiv:2507.09271},
  year   = {2025}
}