走向现代数学学术报告 - 余佳洋副教授（No. 587）

报告题目：$L^2$ methods in infinite dimensional spaces

报 告人：余佳洋 副教授(四川大学)

报告时间：2023年3月30日 上午10点

报告地点：学术报告厅（工西416）

报告摘要：The classical $L^2$ estimate for the $\overline{\partial}$ operators is a basic tool in complex analysis of several variables. Naturally, it is expected to extend this estimate to infinite dimensional complex analysis, but this is a longstanding unsolved problem, due to the essential difficulty that there exists no nontrivial translation invariance measure in the setting of infinite dimensions. The main purpose in this series of work is to give an affirmative solution to the above problem, and apply the estimates to the solvability of the infinite dimensional $\overline{\partial}$ equations. In this first part, we focus on the simplest case, i.e., $L^2$ estimates and existence theorems for the $\overline{\partial}$ equations on the whole space of $\ell^p$ for $p\in [1,\infty)$. The key of our approach is to introduce a suitable working space, i.e., a Hilbert space for $(s,t)$-forms on $\ell^p$ (for each nonnegative integers $s$ and $t$), and via which we define the $\overline{\partial}$ operator from $(s,t)$-forms to $(s,t+1)$-forms and establish the exactness of these operators, and therefore in this case we solve a problem which has been open for nearly forty years.

报告人简介：余佳洋，2014年博士毕业于复旦大学数学科学学院,现为四川大学数学学院副教授。主要从事泛函分析方向的研究，研究兴趣包括无穷维分析、函数空间上的算子论、算子Lehmer问题等。主持国家自然科学基金青年基金，参与国家自然科学基金重点项目，在 Trans. Amer. Math. Soc.,J.Math.PuresAppl.,Illinois J. Math.和Sci.ChinaMath.发表系列论文。