题目： Polyhedra inscribed in quadrics
报告人：Jean-Marc Schlenker (卢森堡大学理学院院长) Anton Thalmaier (卢森堡大学数学系系主任)
时间：2020年11月12日晚9：00-10：00
链接：https://zoom.com.cn/j/67532621800
密码：929725
摘要：In 1832, Jakob Steiner published a book which opened new perspectives on geometry, and in particular on polyhedra. Among other questions, he asked: what are the combinatorial types of polyehdra that can be realized in $\RR^3$ with their vertices on a quadric? The question is projectively invariant and, up to projective transformation, there are only three quadrics in $\RR^3$. The question was first answered in the 1990s for polyhedra inscribed in an ellipsoid, using hyperbolic geometry. I will explain this result and how the question can be answered for the other two quadrics using anti-de Sitter and Half-pipe geometry. (New results are joint work with Jeff Danciger and Sara Maloni.)
备注： 报告将持续40分钟，另加20分钟交流项目简介