【数学学院】9.29 The Kozlov completeness problem

报告题目：The Kozlov completeness problem

报告人：郭坤宇 (复旦大学数学科学学院教授)

报告时间：2019年9月29日  下午16：00-17：00

报告地点：数学学院西303

报告摘要: The classical completeness problem raised by Beurling and       independently by Wintner asks for which $\psi\in L^2(0,1)$, the dilation      system $\{\psi(kx):k=1,2,\cdots\}$ is complete in $L^2(0,1)$, where $\psi$  is identified with its extension to an odd $2$-periodic function on $\mathbb{R}$. This difficult problem is nowadays commonly called as the Periodic Dilation Completeness Problem (PDCP). When $0<s\leq 1$, let $\chi_s$ be the characteristic function of $[0,s]$, and $\mathcal{D}_s=\{\chi_s（kx):k=1,2,\cdots\}$. The Kozlov completeness problem is to ask for which $s$, the dilation system $\mathcal{D}_s$ is complete. In this talk, we give a brief     introduction for the Periodic Dilation Completeness Problem and the Kozlov completeness problem, and present some significant progress on this topic. This is a joint work with Dr.Dan.

来源链接：http://math.scu.edu.cn/info/1062/6015.htm