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2018/93/3-4 (8) — DOI: 10.5486/PMD.2018.8130 — pp. 413-424

Random power series near the endpoint of the convergence interval

Authors: Balázs Maga and Péter Maga

Abstract:

In this paper, we are going to consider power series $$ \sum_{n=1}^{\infty}a_nx^n, $$ where the coefficients $a_n$ are chosen independently at random from a finite set with uniform distribution. We prove that if the expected value of the coefficients is $0$, then $$ \limsup_{x\to 1-}\sum_{n=1}^{\infty}a_nx^n=\infty,\qquad\liminf_{x\to 1-}\sum_{n=1}^{\infty}a_nx^n=-\infty, $$ with probability $1$. We investigate the analogous question in terms of Baire categories.

Keywords: real random power series, boundary behaviour, zero-one laws, residuality

Mathematics Subject Classification: 60F20, 11A63, 54E52