An upper bound for the regularity of powers of edge ideals

Document Type : Research Paper

Author

Department of Mathematics‎, ‎Science and Research Branch‎, ‎Islamic Azad University (IAU)‎, ‎Tehran‎, ‎Iran.

Abstract

‎A recent result due to Ha and Van Tuyl proved that the Castelnuovo-Mumford regularity of the quotient ring $R/I(G)$ is at most matching number of $G$‎, ‎denoted by match$(G)$‎. ‎In this paper‎, ‎we provide a generalization of this result for powers of edge ideals‎. ‎More precisely‎, ‎we show that for every graph $G$ and every $s\geq 1$‎, ‎$${\rm reg}( R‎/ ‎I(G)^{s})\leq (2s-1) |E(G)|^{s-1} {\rm match}(G).$$‎

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S. Beyarslan, H.T. Hà and T.N. Trung, Regularity of powers of forests and cycles, J. Algebraic Combin. 42 (2015) 1077--1095.
S.D. Cutkosky, J. Herzog and N.V. Trung, Asymptotic behaviour of the Castelnuovo Mumford regularity, Compos. Math. 118 (1999) 243--261.
H.T. Hà and A. Van Tuyl, Monomial ideals, edge ideals of hypergraphs, and their graded Betti numbers, J. Algebraic Combin. 27 (2008), no. 2, 215--245.
H.T. Hà and R. Woodroof, Results on the regularity of square-free monomial ideals, Adv. Appl. Math. 58 (2014) 21--36.
M. Katzman, Characteristic independence of Betti numbers of graph ideals, J. Combin Theory Ser. A 113 (2006), no. 3, 435--454.
V. Kodiyalam, Asymptotic behaviour of Castelnuovo-Mumford regularity, Proc. Amer. Math. Soc. 128 (2000), no. 2, 407--411.
M. Kummini, Regularity, depth and arithmetic rank of bipartite edge ideals, J. Algebraic Combin. 30 (2009), no. 4, 429--445.
M. Moghimian, S.A. Seyed Fakhari and S. Yassemi, Regularity of powers of edge ideal of whiskered cycles, Comm. Algebra 45 (2017), no. 3, 1246--1259.