The Ideal Generation Conjecture for 28 Points in P3
Canadian journal of mathematics, Tome 38 (1986) no. 5, pp. 1228-1238

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The ideal generation conjecture has recently been proved for general points in , (k a field) [1], [6]. The proof in [1] is by induction. One of the starting points for the induction (called A(5) in [1]) is proved in [6]. The theoretical proof of A(5) in [6] seems to be very difficult, apparently even more difficult than the induction. Because of this, and also because [6] is not publically available, I feel it is worth knowing that A(5) can be proved numerically with modest readily available computing facilities. In this note I discuss the computation involved, and give a few explicit examples. In the course of working out these examples I found 26 points in , that satisfy the ideal generation conjecture, but which cannot be extended to 27 or 28 points satisfying the ideal generation conjecture. This phenomenon can be interpreted combinatorially, leading to an infinite number of similar examples.
Roberts, Leslie G. The Ideal Generation Conjecture for 28 Points in P3. Canadian journal of mathematics, Tome 38 (1986) no. 5, pp. 1228-1238. doi: 10.4153/CJM-1986-062-x
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[1] 1. Ballico, E., Generators for the homogeneous ideal of s general points in 3 , (preprint). Google Scholar | DOI

[2] 2. Geramita, A. V., Gregory, D. and Roberts, L., Monomial ideals and points in projective space, Journal of Pure and Applied Algebra 40 (1986), 33–62. Google Scholar

[3] 3. Geramita, A. V. and Orecchia, F., On the Cohen-Macaulay type of s lines in An + 1 J. Alg. 70 (1981), 116–140. Google Scholar

[4] 4. Hartshorne, R., Connectedness of the Hilbert scheme, Publ. Math. Inst, des Hautes Etudes Sci. 29 (1966), 261–304. Google Scholar

[5] 5. Hartshorne, R., Algebraic geometry (Springer-Verlag, 1977). Google Scholar | DOI

[6] 6. Hirschowitz, A., letter to R. Hartshorne, (1983). Google Scholar

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