关于举行Dong Han Kim教授（韩国东国大学）学术报告会的通知

报告主题: On the irrationality exponent of real numbers with low complexity expansions

报 告 人: Dong Han Kim 教授（韩国东国大学）

报告时间：2026年11月6日（星期五）上午10:30-11:30

报告地点：4号楼224

邀 请 人: 李兵 教授

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数学学院

2026年10月29日

报告摘要：

Let $\xi$ be a real number and $b \geq 2$ be an integer. We study the relationship between the irrationality exponent of $\xi$ and the subword complexity of the $b$-ary expansion of $\xi$. If the irrationality exponent of $\xi$ is greater than 2, then the subword complexity of the $b$-ary expansion of $\xi$ cannot be too small. 

In this talk, we show that the limit superior of the subword complexity, normalized by the subword length $n$, is at least 4/3 for any $\xi$ whose irrationality exponent is greater than 2.

This is joint work with Yann Bugeaud and Hajime Kaneko.