Elementary Deuring-Heilbronn Phenomenon

Abstract

Adapting a technique of Pintz, we give an elementary demonstration of the Deuring phenomenon: a zero of \zeta(s) off the critical line gives a lower bound on L(1,\chi). The necessary tools are Dirichlet's 'method of the hyperbola', Euler summation, summation by parts, and the Polya-Vinogradov inequality.Comment: Minor revisions per referee's comments. To appear in Acta Arithmetic