A Pellian equation with primes and applications to D(-1)-quadruples

Abstract

In this paper, we prove that the equation $x^2-(p^{2k+2}+1)y^2=-p^{2l+1}$, $l\in \{0,1,\dots ,k\},k\ge 0$, where $p$ is an odd prime number, is not solvable in positive integers $x$ and $y$. By combining that result with other known results on the existence of Diophantine quadruples, we are able to prove results on the extensibility of some $D(-1)$-pairs to quadruples in the ring $\mathbb{Z}[\sqrt{-t}],t>0$.

14 pages