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