English

Integers representable as a difference of two rational fourth powers

General Mathematics 2026-04-28 v2

Abstract

In Section 6.6 of the book {\it Number Theory, Volume I: Tools and Diophantine Equations, Graduate Texts in Mathematics, Volume 239, Springer (2007)}, Cohen investigated the solubility of the equation n=x4+y4n=x^4+y^4 in the rational numbers x,yx,y for all positive integers n10000n \leq 10000. Motivated by this, we investigate the equation n=x4y4n=x^4-y^4 and obtain the complete list of positive integers n10000n\leq 10000 that can be represented in this form for some nonzero rational numbers xx and yy.

Keywords

Cite

@article{arxiv.2604.15832,
  title  = {Integers representable as a difference of two rational fourth powers},
  author = {Ashleigh Ratcliffe and Tho Nguyen Xuan},
  journal= {arXiv preprint arXiv:2604.15832},
  year   = {2026}
}
R2 v1 2026-07-01T12:14:02.692Z