Abstract
The notion of order ideal is no doubt implicit in a paper by Serre in 1958 on free summands of projective modules. A formal definition is given by Bass. However, any algebraist contemplating the question, βon what locus of prime ideals in Spec(R) does an element e in a module E generate a free summand?β, has in fact encountered the concept of an order ideal. In the account on order ideals and their applications in this paper, it is our intent to elaborate on four basic theorems - as we see them - that give insight into the height properties of these ideals. We do this both from a historical view as well as a view of their utility.
Access this chapter
Tax calculation will be finalised at checkout
Purchases are for personal use only
Notes
- 1.
Throughout the remainder of this section when discussing kth syzygy modules E of finite projective dimension we assume that the ring R satisfies the Serre condition (S k ). (For definition see [22, p. 3].)
References
Auslander, M., Buschbaum, D.: Codimension and multiplicity. Ann. Math. 68, 625β657 (1958)
Auslander, M., Bridger, M.: Stable module theory. In: Memoirs of the American Mathematical Society, vol. 94. American Mathematical Society, Providence (1969)
Avravov, L.: Infinite free resolutions. Six lectures on commutative algebra. Progr. Math. 166, 1β118 (1998)
Bass, H.: K-Theory and stable algebra. Publications MathΓ©matiques, No. 22, IHES, Paris (1964)
Bruns, W.: βJedeβ endliche freie AuflΓΆsung is freie AuflΓΆsung eines von drei elementen erzeugten Ideals. J. Algebra 39, 429β439 (1976)
Bruns, W.: The EisenbudβEvans principal ideal theorem and determinantal ideals. Proc. Amer. Math. Soc. 83, 19β24 (1981)
Bruns, W.: The EvansβGriffith Syzygy theorem and Bass numbers. Proc. Amer. Math. Soc. 115(4), 939β946 (1992)
Bruns, W., Herzog, J.: CohenβMacaulay rings. In: Cambridge Studies in Advanced Mathematics, vol. 39. Cambridge University Press, Cambridge (1993)
Buchsbaum, D., Eisenbud, D.: Lifting modules and a theorem on finite free resolutions. In: Ring Theory, pp. 63β64. Academic, New York (1972)
Buchsbaum, D., Eisenbud, D.: What makes a complex exact? J. Algebra 13, 259β268 (1973)
Charalambous, H.: Betti numbers of multigraded modules. J. Algebra 137(2), 491β500 (1991)
Charalambous, H., Evans, E.G.: A deformation theory approach to Betti numbers of finite length modules. J. Algebra 143(1), 246β251 (1991)
Dutta, S.P.: On the canonical element conjecture. Trans. Amer. Math. Soc. 299, 803β811 (1987)
Dutta, S.P., Griffith, P.: Intersection multiplicities, the canonical element conjecture and the syzygy problem. Michigan Math. J. 57, 227β247 (2008)
Eisenbud, D., Evans, E.G.: Generating modules efficiently: theorems from algebraic K-theory. J. Algebra 27, 278β305 (1973)
Eisenbud, D., Evans, E.G.: A generalized principal ideal theorem. Nagoya Math. J. 62, 41β53 (1976)
Eisenbud, D., Huneke, C., Ulrich, B.: Order ideals and a generalized Krull height theorem. Math. Ann. 330(3), 417β439 (2004)
Eisenbud, D., Huneke, C., Ulrich, B.: Heights of ideals of minors. Amer. Math. J. 126(2), 417β438 (2004)
Evans, E.G., Griffith, P.: The syzygy problem. Ann. Math. (2) 114, 323β333 (1981)
Evans, E.G., Griffith, P.: Order ideals of minimal generators. Proc. Amer. Math. Soc. 86, 375β378 (1982)
Evans, E.G., Griffith, P.: The syzygy problem: A new proof and historical perspective. Commutative algebra (Durham 1981). In: London Mathematical Society Lecture Note Series, vol. 72. Cambridge University Press, Cambridge (1982)
Evans, E.G., Griffith, P.: Syzygies. In: London Mathematical Society Lecture Note Series, vol. 106. Cambridge University Press, Cambridge (1985)
Evans, E.G., Griffith, P.: Syzygies: the codimension of zeros of a nonzero section. Algebraic Geometry, Bowdin, pp. 485β489 (1985). Proceedings of Symposium in Pure Mathematics, vol. 46, part 2, American Mathematical Society, Providence, RI (1987)
Evans, E.G., Griffith, P.: Binomial behavior of Betti numbers for modules of finite length. Pacific Math. J. 133(2), 267β276 (1988)
Evans, E.G., Griffith, P.: Order ideals. Commutative Algebra, Berkeley, CA, pp. 213β225 (1987). Mathematical Sciences Research Institute Publications, vol. 15. Springer, New York (1989)
Evans, E.G., Griffith, P.: A graded syzygy theorem in mixed characteristic. Math. Res. Lett. 8, 605β611 (2001)
Griffith, P., Seceleanu, A.: Syzygy theoremsvia comparison of order ideals on a hypersurface. J. Applied Alg. 216(2), 468β479 (2012)
Hackman, P.: Exterior powers of homology. Ph.D. Thesis, University of Stockholm, Sweden (1969)
Hartshorne, R.: Algebraic Geometry. Springer, New York (1977)
Heitmann, R.: The direct summand conjecture in dimension three. Ann. Math. (2) 156, 695β712 (2002)
Herzog, J., KΓΌhl, M.: On the Betti numbers of finite pure and linear resolutions. Commun. Algebra 12(13β14), 1627β1646 (1984)
Hochster, M.: Topics in the homological theory of modules over commutative rings. In: CBMS Regional Conference Series in Applied Mathematics, vol. 24. American Mathematical Society, Providence, RI (1975)
Hochster, M.: Canonical elements in local cohomology modules and the direct summand conjecture. J. Algebra 84, 503β553 (1983)
Hochster, M., Huneke, C.: Tight Closure, Invariant Theory, and the BrianconβSkoda Theorem. J. Amer. Math. Soc. 3(4), 31β116 (1990)
Lazarsfeld, R., Popa, M.: Derivative complex, BGG correspondence, and numerical inequalities for compact KΓ€hler manifolds. Ivent. Math. 182(3), 605β633 (2010)
Matsumura, H.: Commutative ring theory. In: Cambridge Studies in Advanced Mathematics, vol. 8. Cambridge University Press, Cambridge (1986)
Ogoma, T.: A note on the syzygy problem. Comm. Algebra 17(8), 2061β2066 (1989)
Pareschi, G., Popa, M.: Strong generic vanishing and a higher-dimensional Castelnuovo-de Franchis inequality. Duke J. 150(2), 269β285 (2009)
Peskine, C., Szpiro, L.: Dimension projective finie et cohomologie locale. Inst. Hautes Γtudes Sci. Publ. Math. 42, 49β119 (1973)
Roberts, P.: Le thΓ©orΓ¨m dintersection. C. R. Acad. Sci. Paris SΓ©r. I Math. 304, 177β180 (1987)
Serre, J.-P.: Modules Projectifs et Espaces FibrΓ©s Γ Fibre Vectorielle. Seminaire P. Dubreil, Expose 23, Paris (1957β58)
Serre, J.-P.: Sur les modules projectifs. Seminaire Dubriel-Pisot 2, Expose 13, Paris (1960β61)
Serre, J.-P.: Algebra Locale-Multiplicites. In: Lecture Notes in Mathematics, vol. 11. Springer, Berlin (1965)
Shamash, J.: The PoincarΓ© series of a local ring. J. Algebra 12, 453β470 (1969)
Simon, A.-M.: A corollary to the Evans-Griffith syzygy theorem. Rend. Sem. Mat. Univ. Padova 94, 71β77 (1995)
Acknowledgements
We first met David Eisenbud in the late 1960s at University of Chicago. David and the first author were graduate students and the second author was a post-doctoral fellow. Even at this young age David was a catalyst in seminars and a central force for ideas at afternoon tea. It was patently clear that he would become a leader in mathematical research and the greater mathematical community. To each of the authors he was an inspirationβespecially in their early work. We conclude by recounting memorable conversations between David Eisenbud, Mike Stillman, and the first author. The essence of these conversations served as motivation for our joint work on syzygies.
In the fall of 1976 the first author was talking with Mike Stillman about computing syzygies of a collection of homogeneous polynomials generating an ideal and realized that if they bounded the degree they were looking at they had a simple set of linear equations over a field. They could solve those and build a complex and check the BuchsbaumβEisenbud criteria for exactness [10]. This was possible to do by hand as the complexes were quite small and the entries were not too complicated. They noticed that if a column in the kth matrix map had entries in the ideal generated by fewer than k of the variables which might as well be x 1, β¦, x k β 1, then that entry was a linear combination of entries of lower degrees. The first author mentioned this to David and he said one should be able to prove this by computing \(\mathrm{Tor}_{k}(R/I,R/(x_{1},\ldots,x_{k-1}))\). It is zero since R modulo the xβs has projective dimension k β 1 but would be nonzero if the syzygy were a minimal generator. Of course it isnβt too hard to see the same proof would show that the order ideal of a minimal generator of a kth syzygy couldnβt be in the annihilator of a finitely generated module of projective dimension less than k (see Theorem 4β, Sect. 1). Thus a CohenβMacaulay module over R modulo the order ideal of a minimal generator of a kth syzygy would be useful. Alas it took the authors some time to realize that. Happily Mike went to Harvard and met David Bayer. They learned about Grobner bases and created the first version of Macaulay. The authors then used Macaulay to compute lots of resolutions. Eventually they understood how to use the above ideas to formulate a version of the improved new intersection theorem that applied to order ideals of minimal generators which led to the proof of their syzygy theorem.
Author information
Authors and Affiliations
Corresponding author
Editor information
Editors and Affiliations
Rights and permissions
Copyright information
Β© 2013 Springer Science+Business Media New York
About this chapter
Cite this chapter
Evans, E.G., Griffith, P. (2013). A Brief History of Order Ideals. In: Peeva, I. (eds) Commutative Algebra. Springer, New York, NY. https://doi.org/10.1007/978-1-4614-5292-8_12
Download citation
DOI: https://doi.org/10.1007/978-1-4614-5292-8_12
Published:
Publisher Name: Springer, New York, NY
Print ISBN: 978-1-4614-5291-1
Online ISBN: 978-1-4614-5292-8
eBook Packages: Mathematics and StatisticsMathematics and Statistics (R0)