报告题目：Converting Z5-flows to integer 7-flows in signed graphs

报 告 人：韩苗苗，天津师范大学

报告摘要：A concept of flows on signed graphs naturally comes from the dual of local tensions of graphs embedded on non-orientable surfaces. It was conjectured by Bouchet in 1983 that every flow-admissible signed graph admits a nowhere-zero integer 6-flow. The recent 11-flow theorem of signed graphs, obtained by DeVos et al.(JCTB2021), is established by proving the existence of a balanced Z2\times Z3-flow, and then converting Z2-, Z3-flows to integer 3-, 5-flows, respectively. It is crucial to study on how to convert Zk-flows to better integer flows. In this talk, we will show that every bridgeless signed graph with a nowhere-zero Z5-flow admits a nowhere-zero integer 7-flow.

报告人简介：韩苗苗，天津师范大学讲师、硕士生导师，天津市131创新人才（第三层次）。2018年博士毕业于美国西弗吉尼亚大学，导师为赖虹建教授和罗荣教授。主要研究方向为图论中的整数流、群连通以及图染色问题。在本领域重要期刊如J. Combin. Theory Ser. B.，SIAM J. Discrete Math., J. Graph Theory等共发表学术论文20余篇。主持国家自然科学基金青年项目和天津师范大学引进人才基金项目各1项，参与天津市自然科学基金项目2项。

报告时间：2023年6月13日 10:00-11:00

报告地点：文渊楼B119

主办单位：伟德国际1946源自英国