The rational-transcendental dichotomy of Mahler functions
  In this paper, we give a new proof of a result due to Bezivin that a D-finite Mahler function is necessarily rational. This also gives a new proof of the rational-transcendental dichotomy of Mahler functions due to Nishioka. Using our method of proof, we also provide a new proof of a Polya-Carlson type result for Mahler functions due to Rande; that is, a Mahler function which is meromorphic in the unit disk is either rational or has the unit circle as a natural boundary. 
Jason P. Bell, Michael Coons, Eric Rowland
math.CV math.NT