报告人：吴叶舟，博士，浙江大学
报告时间：2017年11月6日14:30
报告地点：数计学院4号楼229室
报告题目：Circuit Covers of Signed Graphs
报告人简介：吴叶舟博士，任职浙江大学海洋学院传感与网络研究所。2003年于中国科技大学获学士学位，2006年于中国科技大学获硕士学位，导师为徐俊明教授，2007年1月至2012年7月于美国西弗吉尼亚大学数学系攻读博士学位，师从张存铨教授；2012年7月至2014年6月在香港大学数学系做博士后研究，合作导师为臧文安教授；2014年9月入职浙江大学海洋学院。
报告摘要：A signed graph is a graph G associated with a mapping \sigma: from E(G) to \{1,-1\}，denoted by $(G,\sigma)$. A cycle of $(G,\sigma)$ is a connected 2-regular subgraph. A cycle C is positive if it has an even number of negative edges, and negative otherwise. The definition of circuit of signed graph comes from the signed-graphic matroid. A circuit cover of $(G,\sigma)$ is a family of positive cycles and barbells covering all edges of $(G,\sigma)$. A circuit cover with the smallest total length is called a shortest circuit cover. Bouchet proved that a signed graph with a circuit cover if and only if it is has a nowhere-zero integer ow). In this talk, we introduce some recent developments of the circuit covers of signed graphs.
This is joint work with Dong Ye.
