THE PROJECTIVE DIMENSION OF THE EDGE IDEAL OF A VERY WELL-COVERED GRAPH

Autor: Naoki Terai, Kyouko Kimura, Siamak Yassemi
Rok vydání: 2017
Předmět:
Zdroj: Nagoya Mathematical Journal. 230:160-179
ISSN: 2152-6842
0027-7630
Popis: A very well-covered graph is an unmixed graph whose covering number is half of the number of vertices. We construct an explicit minimal free resolution of the cover ideal of a Cohen–Macaulay very well-covered graph. Using this resolution, we characterize the projective dimension of the edge ideal of a very well-covered graph in terms of a pairwise$3$-disjoint set of complete bipartite subgraphs of the graph. We also show nondecreasing property of the projective dimension of symbolic powers of the edge ideal of a very well-covered graph with respect to the exponents.
Databáze: OpenAIRE