Icosahedral Polynomials

Abstract

A polynomial is said to be invariant for a group of linear fractional transformations G if its roots are permuted by G. We begin by using a simple group of linear fractional transformations that is isomorphic to S_{3} and finding its invariant polynomials to build up the tools necessary to attack a larger group. We then follow a construction from Toth of the icosahedral group I, and derive a general formula for all polynomials of degree 60 that are invariant under I.