Dear all, Invitation link for Zoom meeting: You all are cordially invited. Location: Freie Universität Berlin Takustr. 9 14195 Berlin Time: Monday, May 9 - 14:15 Lecture: Andrew Newman (Carnegie Mellon University, Pittsburgh) Title: Complexes of nearly maximum diameter Abstract:The combinatorial diameter of a simplicial complex is the diameter of its dual graph. Using a probabilistic approach we determine the right first-order asymptotics for the maximum possible diameter among all d-complexes on n vertices as well as among all d-pseudomanifolds on n vertices. This is joint work with Tom Bohman. Coffee & Tea Break : Room 134 - 1st Floor Time: Monday, May 9 - 16:00 s.t. Colloquium: Marcel Celaya (ETH, Zürich) Title: Improving the Cook et al. Proximity Bound Given Integral Valued Constraints Abstract:Given an optimal solution to a linear program, how far away can a nearest optimal integral solution be? In 1986 Cook, Gerards, Schrijver, and Tardos gave a bound for this distance, known as proximity, which depends only on the dimension and the largest possible magnitude of any subdeterminant of the corresponding constraint matrix. In this talk I will briefly survey this problem, describe some long standing related conjectures, and highlight some recent developments including a recent improvement to the Cook et al. bound when the dimension is at least 2. This is joint work with Joseph Paat, Stefan Kuhlmann, and Robert Weismantel. |