2023/12/11 by Gayfulin, Dmitry, Hauke, Manuel · 1 citation
#11J70 #26D05 #FOS: Mathematics #Number Theory (math.NT)
paper · doi:10.48550/arxiv.2312.06548
Given an irrational number α, we study the asymptotic behaviour of the Sudler product denoted by PN(α) = ∏r=1N 2| sin πr α|. We show that \liminfN → ∞ PN(α) >0 and \limsupN → ∞ PN(α)/N < ∞ whenever the sequence of partial quotients in the continued fraction expansion of α exceeds 3 only finitely often, which confirms a conjecture of the second-named author and partially answers a question of J. Shallit. Furthermore, we show that the Hausdorff dimension of the set of those α that satisfy \limsupN → ∞ PN(α)/N < ∞,\liminfN → ∞ PN(α) >0 lies between 0.7056 and 0.8677, which makes significant progress in a question raised by Aistleitner, Technau, and Zafeiropoulos. We also show that the set of such α is invariant under the Gauss map T.