Cohen-Macaulay clutters with combinatorial optimization properties and parallelizations of normal edge ideals

Abstract

LetC be a uniform clutter and let I = I(C) be its edge ideal. We prove that if C satisfies the packing property (resp. max-flow min-cut property), then there is a uniform Cohen-Macaulay clutter C1 satisfying the packing property (resp. max-flow min-cut property) such that C is a minor of C1. For arbitrary edge ideals of clutters we prove that the normality property is closed under parallelizations. Then we show some applications to edge ideals and clutters which are related to a conjecture of Conforti and Cornu´ejols and to max-flow min-cut problems. 2000 Mathematics Subject Classification: Primary 13H10; Secondary 13F20, 13B22, 52B20.