The Distribution of the Cusped Hypocycloidal Mahler Measure

Abstract

We explore generalized Mahler measures associated to regions in the complex plane. These generalized Mahler measures describe the complexity of polynomials in C[x] by comparing the geometry of their roots to subsets of C. Citing past work connecting the Mahler measure to the unit disk and the reciprocal Mahler measure to the interval [-2,2], we explore a family of cusped hypocycloidal Mahler measures mu^(N) associated to the (N+1)-cusped hyplocycloids, using potential theory to show how a generalized Mahler measure may be constructed from Jensen's formula.Let s be a complex variable, and d a positive integer. To every generalized Mahler measure Phi we define the complex moment function Hd(Phi; s) which provides information about the range of values Phi takes on degree d polynomials in C[x]. These functions are analytic in the half-plane R(s)>d. We will show how Hd(s) may be represented as the determinant of a Gram matrix in a Hilbert space determined by Phi and s. We thus discover properties of Hd(mu^(N); s) as a rational function of s.