报告题目：Nowhere-zero integer flows of signed graphs (II)
报告人：Professor Cun-Quan Zhang
       West Virginia University
报告时间：5月20日 14：00-15：00
报告地点：管理科研楼1518

摘要: The well-known Bouchet's conjecture is that every signed graph admitting a nowhere-zero integer ow admits a nowhere-zero integer 6-flow. This conjecture remains open, although it has been extensively researched and studied, such as, Raspaud and Zhu confirmed the conjecture for 4-edge-connected graphs [JCTB 2011]. Without the requirement of edge-connectivity, Zýka proved the conjecture with 6 replaced by 30. In this talk, we will survey some of those early results under various edge-connectivity conditions, and some new results under some graph minor condition but no or less requirement of edge-connectivity. If time allows, outlines of proofs will also be presented.

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