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Postulation of a General Union of an m-Point and a General Smooth Rational Curve

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Abstract

In this paper, we consider the problem of determining the Hilbert function of a general union \({X\subset \mathbb{P}^n}\) of an m-point mP and a general smooth rational curve of degree s. If \({n\geq 4}\), then X has the expected Hilbert function, i.e., X has maximal rank. If n = 3, then there are exceptional cases (if \({3\leq s\leq m}\)). We conjecture that these are the only exceptional cases and we prove this conjecture in several cases (e.g., if \({s\gg m}\)).

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References

  1. Ballico E.: On the postulation of disjoint rational curves in a projective space. Rend. Sem. Mat. Univ. Politec. Torino 44(2), 207–249 (1986)

    MATH  MathSciNet  Google Scholar 

  2. Ballico E., Ellia P.H.: Generic curves of small genus in \({\mathbb {P}^3}\) are of maximal rank. Math. Ann. 264, 211–225 (1983)

    Article  MATH  MathSciNet  Google Scholar 

  3. Ballico, E., Ellia, P.H.: On the postulation of many disjoint rational curves in \({\mathbb {P}_N}\), \({N \geq 4}\). Boll. Un. Mat. Ital. B (6) 4(2), 585–599 (1985)

  4. Ballico E., Ellia P.H.: The maximal rank conjecture for non-special curves in \({\mathbb {P}^3}\). Invent. Math. 79, 541–555 (1985)

    Article  MATH  MathSciNet  Google Scholar 

  5. Carlini, E., Catalisano, M.V., Geramita, A.V.: Reduced and non-reduced linear spaces: lines and points, arXiv:1308.0796

  6. Fatabbi, G., Harbourne, B., Lorenzini, A.: Inclics, galaxies, star configurations and Waldschimdt constants, arXiv:1304.2217

  7. Eisenbud, D., Van de Ven A.: On the normal bundles of smooth rational space curves. Math. Ann. 256(4), 453–463 (1981)

  8. Ghione F., Sacchiero G.: Normal bundles of rational curves in \({\mathbb{P}^3}\). Manuscr. Math. 33, 111–128 (1980)

    Article  MATH  MathSciNet  Google Scholar 

  9. Hartshorne, R.: Algebraic geometry, Graduate Texts in Mathematics, vol. 52. Springer, Berlin (1977)

  10. Hartshorne, R., Hirschowitz, A.: Droites en position générale dans \({\mathbb {P}^n}\), Algebraic geometry. In: Proceedings, La Rábida 1981, Lecture Notes in Mathematics. vol. 961, pp. 169–188. Springer, Berlin (1982)

  11. Hartshorne, R., Hirschowitz, A.: Smoothing algebraic space curves, In: Algebraic geometry, Sitges 1983, Lecture Notes in Mathematics, vol. 1124, pp. 98–131. Springer, Berlin (1985)

  12. Hirschowitz A.: Sur la postulation générique des courbes rationnelles. Acta Math. 146, 209–230 (1981)

    Article  MATH  MathSciNet  Google Scholar 

  13. Perrin, D.: Courbes passant par m points généraux de \({\mathbb {P}^3}\). Bull. Soc. Math. Fr. Mém. No. 28/29 (1987)

  14. Sernesi E.: On the existence of certain families of curves. Invent. Math. 75(1), 25–57 (1984)

    Article  MATH  MathSciNet  Google Scholar 

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Correspondence to E. Ballico.

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The author was partially supported by MIUR and GNSAGA of INdAM (Italy).

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Ballico, E. Postulation of a General Union of an m-Point and a General Smooth Rational Curve. Mediterr. J. Math. 12, 281–300 (2015). https://doi.org/10.1007/s00009-014-0418-x

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  • DOI: https://doi.org/10.1007/s00009-014-0418-x

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