这是群论和图论方向的线上系列报告，我们希望能够促进国内外青年学者（博士生为主）在群论和图论研究上的交流。报告主题分布在（但不限于）以下研究方向：
This is a platform for young group theorists and graph theorists (mostly PhD students) to talk about their research and related topics online. The topic can be anything related to group theory and graph theory, including but not limited to the following.
一般地，系列报告定期于北京时间每周三下午16:00-17:00进行。
Our usual time is Wednesday 16:00-17:00 (GMT+8).
Title: Cliques in derangement graphs
Speaker: Marco Fusari (University of Pavia)
Time: 16:00-17:00 (GMT+8), Tuesday April 29th
Location: Zoom: 262 780 8767 (passcode: gts2025)
Abstract:
Given a permutation group \(G\), the derangement graph \(\Gamma G\) of \(G\) is the Cayley graph with connection set the derangements of \(G\). In a recent paper of 2021 Meagher, Razafimahatratra and Spiga conjectured that there exists a function \( f : N \to N\) such that, if \(G\) is transitive of degree \(n\) and \(\Gamma G\) has no \(k\)-clique, then \(n\le f(k)\). The conjecture has been proved for innately transitive groups, that are a generalization of primitive groups. Motivation for this work arises from investigations on Erdos-Ko-Rado type theorems for permutation groups. (Join work with P.Spiga and A.Previtali)
The seminar is currently based at the Southern University of Science and Technology (SUSTech, 南方科技大学).