Abstract
For a minimal free resolution of a Stanley-Reisner ring constructed from the order complex of a modular lattice. T. Hibi showed that its last Betti number (called the Cohen-Macaulay type) is computed by means of the Möbius function of the given modular lattice. Using this result, we consider the Stanley-Reisner ring of the subgroup lattice of a finite abelianp-group associated with a given partition, and show that its Cohen-Macaulay type is a polynomial inp with integer coefficients.
Similar content being viewed by others
References
Birkoff, G.: Subgroups of abelian groups. Proc. London Math. Soc.(2) 38, 385–401 (1934–35)
Bruns-J. Herzog-W.: Cohen-Macaulay Rings, Cambridge University Press, Cambridge/New York/Sydney (1993)
Butler, L.: A unimordality result in the enumeration of subgroups of a finite abelian group. Proc. Am. Math. Soc.(4) 101, 771–775 (1987)
Hibi, T.: Cohen-Macaulay types of Cohen-Macaulay complexes. J. Algebra168, 780–797 (1994)
Hibi, T.: Homological and combinatorial study of Stanley-Reisner rings of simplicial complexes. Research Report 93-54, School of Mathematics and Statistics, University of Sydney, November (1993)
Macdonald, I.G.: Symmetric functions and Hall polynomials, Oxford University Press (1979)
Stanley, R.: Enumerative combinatorics, volume 1, Wardsworth-Brooks/Cole, Monterey, Calif. (1986)
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Morita, H. Cohen-Macaulay types of subgroup lattices of finite abelianp-groups. Graphs and Combinatorics 11, 275–283 (1995). https://doi.org/10.1007/BF01793015
Received:
Issue Date:
DOI: https://doi.org/10.1007/BF01793015