English

The quotient problem for linear recurrence sequences

Number Theory 2026-05-08 v1

Abstract

Let {U(m)}mN\{U(m)\}_{m\in \N} and {V(n)}nN\{V(n)\}_{n\in \N} be linear recurrence sequences. It is a well-known Diophantine problem to determine the finiteness of the set of natural numbers nn such that the ratio U(n)/V(n)U(n)/V(n) is an integer. We study the finiteness problem for the set (m,n)N2(m, n)\in \mathbb{N}^2 such that there exist non-zero positive integers dm,nd_{m, n} satisfying logdm,n=o(n)\log |d_{m, n}|=o(n), and dm,nU(m)/V(n)d_{m, n}U(m)/V(n) is an element from a finitely generated subring of \C\C. In particular, we prove that for mnm\neq n , there exists a polynomial PP such that dm,nP(n)U(m)/V(n)d_{m, n}P(n)U(m)/V(n) is a multi-recurrence and V(n)/P(n)V(n)/P(n) is a linear recurrence and for m=nm=n both dm,nP(n)U(m)/V(n)d_{m, n}P(n)U(m)/V(n) and V(n)/P(n)V(n)/P(n) are linear recurrences. To prove our results, we employ Schmidt's subspace theorem, and the concept of moving hyperplanes, moving polynomials, and moving points.

Keywords

Cite

@article{arxiv.2605.05784,
  title  = {The quotient problem for linear recurrence sequences},
  author = {Parvathi S Nair and S. S. Rout},
  journal= {arXiv preprint arXiv:2605.05784},
  year   = {2026}
}
R2 v1 2026-07-01T12:54:16.089Z