讲座人简介：

王利广曲阜师范大学教授，博士生导师。2005年7月于中国科学院获理学博士学位。研究方向为泛函分析和算子代数。目前正在主持国家自然科学基金面上项目一项，主持山东省自然科学基金面上项目一项；已主持完成国家自然科学基金面上项目和数学天元基金各一项、山东省自然科学基金面上项目一项。已在《J. Functional Analysis》、《J. Operator Theory》等期刊发表论文20余篇。

讲座简介：

Wigner's theorem shows that every transition probability preserving surjection on the set of all rank one projections on a Hilbert space is induced by a unitary or an antiunitary. Wigner's theorem can be interpreted as a result of mappings that preserves certain metric on the set of projections. Recently, Geh\'{e}r and \u{S}emrl have characterized the general form of surjective isometries of the set of all projections on an infinite-dimensional separable Hilbert space using unitaries and antiunitaries. In this talk, we will study the surjective $L^2$-isometries of the projection lattice of an infinite dimensional Hilbert space and show that every such isometry can also be described by unitaries and antiunitaries. This talk is based on joint work with Wenming Wu and Wei Yuan.