1,217 research outputs found
Bicircular signed-graphic matroids
Several matroids can be defined on the edge set of a graph. Although
historically the cycle matroid has been the most studied, in recent times, the
bicircular matroid has cropped up in several places. A theorem of Matthews from
late 1970s gives a characterization of graphs whose bicircular matroids are
graphic. We give a characterization of graphs whose bicircular matroids are
signed-graphic.Comment: 8 page
Claw-free t-perfect graphs can be recognised in polynomial time
A graph is called t-perfect if its stable set polytope is defined by
non-negativity, edge and odd-cycle inequalities. We show that it can be decided
in polynomial time whether a given claw-free graph is t-perfect
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