Frequencies of digits, divergence points, and Schmidt games

Sets of divergence points, i.e. numbers x (or tuples of numbers) for which the limiting frequency of a given string of N-adic digits of x fails to exist, have recently attracted huge interest in the literature. In this paper we consider sets of simultaneous divergence points, i.e. numbers x (or tuples of numbers) for which the limiting frequencies of all strings of N-adic digits of x fail to exist. We show that many natural sets of simultaneous divergence points are (alpha,beta)-wining sets in the sense of the Schmidt game. As all application we obtain lower bounds for the Hausdorff dimension of these sets. (C) 2007 Elsevier Ltd. All rights reserved.