Cohen’s Theorem and \(Z\)-Cyclic Whist Tournaments

Tan Anderson1, Norman J.Finizio2
1Department of Mathematics University of Glasgow Glasgow, Scotland G12 8QW
2Department of Mathematics University of Rhode Island Kingston, RI 02881

Abstract

Let \(p,q\) denote primes, \(p \equiv 1 \pmod{4}\), \(g \equiv 3 \pmod{4}\), \(g \geq 7\). In an earlier study we established that if \(\gcd(q-1, p^{n-1}(p-1)) = 2\) and if a \(\mathbb{Z}\)-cyclic \(Wh(q+1)\) exists then a \(\mathbb{Z}\)-cyclic \(Wh(qp^n + 1)\) exists for all \(n \geq 0\). Here we consider \(\gcd(qg-1,p^{n-1}(p-1)) > 2\) and prove that if a \(\mathbb{Z}\)-cyclic \(Wh(q+1)\) exists then there exists a \(\mathbb{Z}\)-cyclic \(Wh(qp^n + 1)\) for all \(n \geq 0\). The proof employed depends on the existence of an appropriate primitive root of \(p\). Utilizing a theorem of S. D. Cohen we establish that such appropriate primitive roots always exist.