Illinois Journal of Mathematics

The residuals of lex plus powers ideals and the Eisenbud–Green–Harris conjecture

Benjamin P. Richert and Sindi Sabourin
Source: Illinois J. Math. Volume 52, Number 4 (2008), 1355-1384.

Abstract

The n-type vectors introduced by Geramita, Harima, and Shin are in 1–1 correspondence with the Hilbert functions of Artinian lex ideals. Letting $\mathbb{A}=\{a_{1},\ldots,a_{n}\}$ define the degrees of a regular sequence, we construct $\mathrm{lpp}_{\le }(\mathbb{A})$-vectors which are in 1–1 correspondence with the Hilbert functions of certain lex plus powers ideals (depending on $\mathbb{A}$). This construction enables us to show that the residual of a lex plus powers ideal in an appropriate regular sequence is again a lex plus powers ideal. We then use this result to show that the Eisenbud–Green–Harris conjecture is equivalent to showing that lex plus powers ideals have the largest last graded Betti numbers (it is well known that the Eisenbud–Green–Harris conjecture is equivalent to showing that lex plus powers ideals have the largest first graded Betti numbers).

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Primary Subjects: 13F20, 13D02
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Links and Identifiers

Permanent link to this document: http://projecteuclid.org/euclid.ijm/1258554367
Mathematical Reviews number (MathSciNet): MR2595772
Zentralblatt MATH identifier: 1197.13020

References

A. M. Bigatti, Upper bounds for the Betti numbers of a given Hilbert function, Comm. Algebra 21 (1993), 2317--2334.
Mathematical Reviews (MathSciNet): MR1218500
Zentralblatt MATH: 0817.13007
Digital Object Identifier: doi:10.1080/00927879308824679
H. Charalambous and E. G. Evans, Jr., Private correspondence, 2003.
G. F. Clements and B. Lindström, A generalization of a combinatorial theorem of Macaulay, J. Combinatorial Theory 7 (1969), 230--238.
Mathematical Reviews (MathSciNet): MR0246781
Digital Object Identifier: doi:10.1016/S0021-9800(69)80016-5
Zentralblatt MATH: 0186.01704
A. V. Geramita, D. Gregory and L. Roberts, Monomial ideals and points in projective space, J. Pure Appl. Algebra 40 (1986), 33--62.
Mathematical Reviews (MathSciNet): MR0825180
Zentralblatt MATH: 0586.13015
Digital Object Identifier: doi:10.1016/0022-4049(86)90029-0
A. V. Geramita, P. Maroscia and L. G. Roberts, The Hilbert function of a reduced $k$-algebra, J. London Math. Soc. (2) 28 (1983), 443--452.
Mathematical Reviews (MathSciNet): MR0724713
Zentralblatt MATH: 0535.13012
Digital Object Identifier: doi:10.1112/jlms/s2-28.3.443
A. V. Geramita, M. Pucci and Y. S. Shin, Smooth points of $\mathcal Gor(T)$, J. Pure Appl. Algebra 122 (1997), 209--241.
Mathematical Reviews (MathSciNet): MR1481088
Zentralblatt MATH: 0905.13004
Digital Object Identifier: doi:10.1016/S0022-4049(97)00052-2
A. V. Geramita, T. Harima and Y. S. Shin, An alternative to the Hilbert function for the ideal of a finite set of points in $\Bbb P\sp n$, Illinois J. Math. 45 (2001), 1--23.
Mathematical Reviews (MathSciNet): MR1849983
Zentralblatt MATH: 1095.13500
Project Euclid: euclid.ijm/1258138252
D. R. Grayson and M. E. Stillman, Macaulay 2, a software system for research in algebraic geometry, available at http://www.math.uiuc.edu/Macaulay2/.
C. Greene and D. J. Kleitman, Proof techniques in the theory of finite sets, Studies in combinatorics, MAA Stud. Math., vol. 17, Math. Assoc. America, Washington, DC, 1978, pp. 22--79.
Mathematical Reviews (MathSciNet): MR0513002
Zentralblatt MATH: 0409.05012
H. Hulett, Maximum Betti numbers of homogeneous ideals with a given Hilbert function, Comm. Algebra 21 (1993), 2335--2350.
Mathematical Reviews (MathSciNet): MR1218501
Zentralblatt MATH: 0817.13006
Digital Object Identifier: doi:10.1080/00927879308824680
F. Macaulay, Some properties of enumeration in the theory of modular systems, Proc. London Math. Soc. 26 (1927), 277--334.
J. C. Migliore, Introduction to liaison theory and deficiency modules, Progress in Mathematics, vol. 165, Birkhäuser Boston, Boston, MA, 1998.
Mathematical Reviews (MathSciNet): MR1712469
K. Pardue, Deformation classes of graded modules and maximal Betti numbers, Illinois J. Math. 40 (1996), 564--585.
Mathematical Reviews (MathSciNet): MR1415019
Zentralblatt MATH: 0903.13004
Project Euclid: euclid.ijm/1255985937
B. P. Richert, A study of the lex plus powers conjecture, J. Pure Appl. Algebra 186 (2004), 169--183.
Mathematical Reviews (MathSciNet): MR2025596
Zentralblatt MATH: 1052.13008
Digital Object Identifier: doi:10.1016/S0022-4049(03)00130-0
L. Robbiano, Introduction to the theory of Hilbert functions, The Curves Seminar at Queen's, vol. VII (Kingston, ON, 1990), Queen's Papers in Pure and Appl. Math., vol. 85, Queen's Univ., Kingston, ON, 1990, Exp. No. B, 26.
Mathematical Reviews (MathSciNet): MR1089895
Zentralblatt MATH: 0816.13013
S. Sabourin, Generalized $k$-configurations and their minimal free resolutions, J. Pure Appl. Algebra 191 (2004), 181--204.
Mathematical Reviews (MathSciNet): MR2048313
Zentralblatt MATH: 1077.14081
Digital Object Identifier: doi:10.1016/j.jpaa.2003.12.002

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