====== Jackie Kaminski (Binghamton) ======

====== Circular Flow on Bidirected Graphs ======

===== Abstract for the Combinatorics Seminar 2007 December 4 =====

Bouchet's Conjecture states that every signed graph (equivalent to a bidirected graph) admits a nowhere zero 6-flow.

I will introduce signed and bidirected graphs, circular and integral flows on signed graphs, and the matroid of a signed graph. The main result of this talk will be proving an upper bound on the circular flow number of a signed graph based on the edge connectivity of the underlying graph, which is a partial result towards Bouchet's Conjecture. The proof of this theorem will make use of some elementary facts about the matroid of a signed graph.

The results in this talk are from a paper by Raspaud & Zhu by the same title.


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