• Rong Luo, Modulo flows and Integer flows of signed graphs

    Room B332 IBS (기초과학연구원)

    Nowhere-zero flows of unsigned graphs were introduced by Tutte in 1954 as a dual problem to vertex-coloring of (unsigned) planar graphs. The definition of nowhere-zero flows on signed graphs naturally comes from the study of embeddings of graphs in non-orientable surfaces, where nowhere-zero flows emerge as the dual notion to local tensions.  Nowhere-zero flows in