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Grothendieck–Plücker Images of Hilbert Schemes are Degenerate

Published online by Cambridge University Press:  22 August 2018

Donghoon Hyeon
Affiliation:
Department of Mathematical Sciences, Seoul National University, Seoul, Republic of Korea ([email protected]; [email protected])
Hyungju Park
Affiliation:
Department of Mathematical Sciences, Seoul National University, Seoul, Republic of Korea ([email protected]; [email protected])

Abstract

We study the decompositions of Hilbert schemes induced by the Schubert cell decomposition of the Grassmannian variety and show that Hilbert schemes admit a stratification into locally closed subschemes along which the generic initial ideals remain the same. We give two applications. First, we give completely geometric proofs of the existence of the generic initial ideals and of their Borel fixed properties. Second, we prove that when a Hilbert scheme of non-constant Hilbert polynomial is embedded by the Grothendieck–Plücker embedding of a high enough degree, it must be degenerate.

Type
Research Article
Copyright
Copyright © Edinburgh Mathematical Society 2018 

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References

1.Bayer, D. and Morrison, I., Standard bases and geometric invariant theory. I. Initial ideals and state polytopes, J. Symbolic Comput. 6(2–3) (1988), 209217.Google Scholar
2.Bayer, D. and Stillman, M., A criterion for detecting m-regularity, Invent. Math. 87(1) (1987), 111.Google Scholar
3.Bayer, D. and Stillman, M., A theorem on refining division orders by the reverse lexicographic order, Duke Math. J. 55(2) (1987), 321328.Google Scholar
4.Bertone, C., Lella, P. and Roggero, M., A Borel open cover of the Hilbert scheme, J. Symbolic Comput. 53 (2013), 119135.Google Scholar
5.Brion, M., Lectures on the geometry of flag varieties https://www-fourier.ujf-grenoble.fr/~mbrion/lecturesrev.pdf.Google Scholar
6.Conca, A. and Sidman, J., Generic initial ideals of points and curves, J. Symbolic Comput. 40(3) (2005), 10231038.Google Scholar
7.Crupi, M. and La Barbiera, M., Ideals generated by reverse lexicographic segments, Math. Notes 89(1) (2011), 6881.Google Scholar
8.Eisenbud, D., Commutative algebra, Graduate Texts in Mathematics, Volume 150 Springer-Verlag, New York, 1995).Google Scholar
9.Galligo, A., À propos du théorème de-préparation de Weierstrass, In Fonctions de plusieurs variables complexes (Sém. François Norguet, Octobre 1970–Décembre 1973; edité par François Norguet; à la mémoire d’André Martineau), Lecture Notes in Mathematics, Volume 409, pp. 543579 (Springer, Berlin, 1974). Thèse de 3ème cycle soutenue le 16 mai 1973 à l'Institut de Mathématique et Sciences Physiques de l'Université de Nice.Google Scholar
10.Gotzmann, G., Eine Bedingung für die Flachheit und das Hilbertpolynom eines graduierten Ringes, Math. Z. 158(1) (1978), 6170.Google Scholar
11.Green, M. L., Generic initial ideals, In Six lectures on commutative algebra (Bellaterra, 1996) (ed. Elías, J., Giral, J. M., Miró-Roig, R. M. and Zarzuela, S.), pp. 119186, Progress in Mathematics, Volume 166 (Birkhäuser, Basel, 1998).Google Scholar
12.Hartshorne, R., Connectedness of the Hilbert scheme, Inst. Hautes Études Sci. Publ. Math. 29 (1966), 548.Google Scholar
13.Iarrobino, A. and Kanev, V., Power sums, Gorenstein algebras, and determinantal loci, Lecture Notes in Mathematics, Volume 1721 (Springer-Verlag, Berlin, 1999). Appendix C by Iarrobino and Steven L. Kleiman.Google Scholar
14.Marinari, M. G. and Ramella, L., Some properties of Borel ideals, J. Pure Appl. Algebra 139(1–3) (1999), 183200.Google Scholar
15.Notari, R. and Spreafico, M. L., A stratification of Hilbert schemes by initial ideals and applications, Manuscripta Math. 101(4) (2000), 429448.Google Scholar
16.Pardue, K., non-standard borel-fixed ideals, PhD thesis, Brandeis University, ProQuest LLC, Ann Arbor, MI, 1994.Google Scholar
17.Roggero, M. and Terracini, L., Ideals with an assigned initial ideals, Int. Math. Forum 5(53–56) (2010), 27312750.Google Scholar
18.Sherman, M., On an extension of Galligo's theorem concerning the Borel-fixed points on the Hilbert scheme, J. Algebra 318(1) (2007), 4767.Google Scholar
19.Sturmfels, B., Gröbner bases and convex polytopes, University Lecture Series, Volume 8 (American Mathematical Society, Providence, RI, 1996).Google Scholar
20.Valla, G., Problems and results on Hilbert functions of graded algebras, In Six lectures on commutative algebra (Bellaterra, 1996) (ed. Elías, J., Giral, J. M., Miró-Roig, R. M. and Zarzuela, S.), pp. 293344, Progress in Mathematics, Volume 166 (Birkhäuser, Basel, 1998).Google Scholar