The Degree of the Splitting Field of a Random Polynomial over a Finite Field

Abstract

The asymptotics of the order of a random permutation have been widely studied. P. Erdös and P. Turán proved that asymptotically the distribution of the logarithm of the order of an element in the symmetric group $S_{n}$ is normal with mean ${1\over2}(\log n)^{2}$ and variance ${1\over3}(\log n)^{3}$. More recently R. Stong has shown that the mean of the order is asymptotically $\exp(C\sqrt{n/\log n}+O(\sqrt{n}\log\log n/\log n))$ where $C=2.99047\ldots$. We prove similar results for the asymptotics of the degree of the splitting field of a random polynomial of degree $n$ over a finite field.