报告题目: Testing isomorphism of cyclic symmetric configurations

报告时间：2019年9月24日 16:45-17:45

报告地点：数学馆310会议室

报告人：University of Primorska, István Kovács教授

报告摘要：A symmetric (combinatorial) configuration of type is an incidence geometry , consisting of a set of points and a collection of lines (or blocks) such that distinct lines intersect in at most one point, and all lines contain points.  A cyclic configuration has point set , such that the mapping ,

preserves the lines. Two such configurations are said to be multiplier equivalent if one can be mapped to the other by a mapping in the form , where is relatively prime to . It is easy to see that multiplier equivalent configurations are isomorphic. In this talk, I will show that the converse also holds, and hence give a simple isomorphism criterion for cyclic symmetric configurations. As an application, a formula will also be shown for the number of symmetric cyclic configurations of type . The talk is based on joint work with Hiroki Koike, Dragan Marušič, Mikhail  Muzychuk and Tomaž Pisanski.

专家简介：

István Kovács，斯洛文尼亚普利莫斯卡大学(University of Primorska)教授。2003年博士毕业于匈牙利塞格德大学(University of Szeged)，主要从事有限几何和代数组合方面的研究。目前在Transactions of the American Mathematical Society、Journal of Combinatorial Theory Series B(A)、Finite Fields and their Applications、Journal of Algebraic Combinatorics、Journal of Graph Theory、European Journal of Combinatorics等杂志上发表论文50余篇。