Dear all, You all are cordially invited. Location: Technische Universität Berlin Straße des 17. Juni 136 10623 Berlin Time: Monday, July 4 - 14:15 Lecture: Myfanwy Evans (Universität Potsdam) Title: Enumerating triply-periodic tangles Abstract:Using periodic surfaces as a scaffold is a convenient route to making periodic entanglements. I will present a systematic way of enumerating new tangled periodic structures, using low-dimensional topology and combinatorics, posing the question of how to best characterise these new patterns. I will also give an insight into applications of these structures. Coffee & Tea Break : Room MA 316 - Third Floor Time: Monday, July 4 - 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. |