English

The number of representations of squares by integral ternary quadratic forms

Number Theory 2015-10-01 v1

Abstract

Let ff be a positive definite integral ternary quadratic form and let r(k,f)r(k,f) be the number of representations of an integer kk by ff. In this article we study the number of representations of squares by ff. We say the genus of ff, denoted by gen(f)\text{gen}(f), is indistinguishable by squares if for any integer nn, r(n2,f)=r(n2,f)r(n^2,f)=r(n^2,f') for any quadratic form fgen(f)f' \in \text{gen}(f). We find some non trivial genera of ternary quadratic forms which are indistinguishable by squares. We also give some relation between indistinguishable genera by squares and the conjecture given by Cooper and Lam, and we resolve their conjecture completely.

Keywords

Cite

@article{arxiv.1509.09111,
  title  = {The number of representations of squares by integral ternary quadratic forms},
  author = {Kyoungmin Kim and Byeong-Kweon Oh},
  journal= {arXiv preprint arXiv:1509.09111},
  year   = {2015}
}