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On monomial curves obtained by gluing

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Abstract

We study arithmetic properties of tangent cones associated to large families of monomial curves obtained by gluing. In particular, we characterize their Cohen-Macaulay and Gorenstein properties and prove that they have non-decreasing Hilbert functions. The results come from a careful analysis of some special Apéry sets of the numerical semigroups obtained by gluing under a condition that we call specific gluing. As a consequence, we complete and extend the results proved by Arslan et al. (in Proc. Am. Math. Soc. 137:2225–2232, 2009) about nice gluings by using different techniques. Our results also allow to prove that for a given numerical semigroup with a non-decreasing Hilbert function and an integer q>1, all extensions of it by q, except a finite number, have non-decreasing Hibert functions.

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References

  1. Arslan, F.: Cohen-Macaulayness of tangent cones. Proc. Am. Math. Soc. 128, 2243–2251 (2000)

    Article  MATH  MathSciNet  Google Scholar 

  2. Arslan, F., Mete, P.: Hilbert functions of Gorenstein monomial curves. Proc. Am. Math. Soc. 135, 1993–2002 (2007)

    Article  MATH  MathSciNet  Google Scholar 

  3. Arslan, F., Mete, P., Şahin, M.: Gluing and Hilbert functions of monomial curves. Proc. Am. Math. Soc. 137, 2225–2232 (2009)

    Article  MATH  Google Scholar 

  4. Barucci, V., Dobbs, D.E., Fontana, M.: Maximality properties in numerical semigroups and applications to one-dimensional analytically irreducible local domains. Mem. Am. Math. Soc. 125, 598 (1997)

    MathSciNet  Google Scholar 

  5. Bruns, W., Herzog, J.: Cohen-Macaulay Rings. Cambridge Studies in Advanced Mathematics, vol. 39. Cambridge University Press, Cambridge (1998)

    Book  MATH  Google Scholar 

  6. Bryant, L.: Goto numbers of a numerical semigroup ring and the Gorensteiness of associated graded rings. Commun. Algebra 38, 2092–2128 (2010)

    Article  MATH  Google Scholar 

  7. Cortadellas Benítez, T., Zarzuela Armengou, S.: Tangent cones of numerical semigroup rings. Contemp. Math. 502, 45–58 (2009)

    Article  Google Scholar 

  8. Cortadellas Benítez, T., Jafari, R., Zarzuela Armengou, S.: On the Apéry sets of monomial curves. Semigroup Forum 86, 289–320 (2013)

    Article  MATH  MathSciNet  Google Scholar 

  9. D’Anna, M., Micale, V., Sammartano, A.: When the associated graded ring of a semigroup ring is complete intersection. J. Pure Appl. Algebra 216, 1007–1017 (2013)

    Article  MathSciNet  Google Scholar 

  10. Delgado, M., García-Sánchez, P.A., Morais, J.: NumericalSgps-a GAP package 0.95. (2006). See http://www.gap-system.org/Packages/numericalsgps

  11. Garcia, A.: Cohen-Macaulayness of the associated graded of a semigroup ring. Commun. Algebra 10, 393–415 (1982)

    Article  MATH  Google Scholar 

  12. García-Sánchez, P.A., Rosales, J.C.: Numerical Semigroups. Developments in Mathematics, vol. 20. Springer, New York (2009)

    MATH  Google Scholar 

  13. Heinzer, W., Kim, M., Ulrich, B.: The Gorenstein and complete intersection properties of associated graded rings. J. Pure Appl. Algebra 201, 264–283 (2005)

    Article  MATH  MathSciNet  Google Scholar 

  14. Kunz, E.: The value-semigroup of a one-dimensional Gorenstein ring. Proc. Am. Math. Soc. 25, 748–751 (1970)

    Article  MATH  MathSciNet  Google Scholar 

  15. Morales, M., Thoma, A.: Complete intersection lattice ideals. J. Algebra 284, 755–770 (2005)

    Article  MATH  MathSciNet  Google Scholar 

  16. Ooishi, A.: On the Gorenstein property of the associated graded ring and the Rees algebra of an ideal. J. Algebra 155, 397–414 (1993)

    Article  MATH  MathSciNet  Google Scholar 

  17. Reyes, E., Villarreal, R.H., Zárate, L.: A note on affine toric varieties. Linear Algebra Appl. 318, 173–179 (2000)

    Article  MATH  MathSciNet  Google Scholar 

  18. Robbiano, L., Valla, G.: On the equations defining tangent cones. Math. Proc. Camb. Philos. Soc. 88, 281–297 (1980)

    Article  MATH  MathSciNet  Google Scholar 

  19. Rosales, J.C.: Semigrupos numéricos. Tesis Doctoral Universidad de Granada, Spain (1991)

  20. Rosales, J.C.: On presentations of subsemigroups of \(\Bbb{N}^{n}\). Semigroup Forum 55, 152–159 (1997)

    Article  MATH  MathSciNet  Google Scholar 

  21. Rosales, J.C., García-Sánchez, P.A.: On complete intersection affine semigroups. Commun. Algebra 23, 5395–5412 (1995)

    Article  MATH  Google Scholar 

  22. Şahin, M.: Producing set-theoretic complete intersection monomial curves in \(\mathbb{P}^{n}\). Proc. Am. Math. Soc. 137, 1223–1233 (2009)

    MATH  Google Scholar 

  23. Şahin, M.: Extensions of toric varieties. Electron. J. Comb. 18, 93 (2011), 10 pp.

    Google Scholar 

  24. Thoma, A.: Construction of set-theoretic complete intersections via semigroup gluing. Contribut. Algebra Geom. 41(1), 195–198 (2000)

    MATH  MathSciNet  Google Scholar 

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Acknowledgements

This work was initiated during a two months stay in the year 2012 of the first author at the Institute of Mathematics of the University of Barcelona (IMUB), in the frame of its program of visiting researchers. Both authors would like to thank the IMUB for its hospitality and support. Finally, we also would like to thank Tere Cortadellas for a careful reading of this manuscript, and the referee for several good suggestions to improve the clarity of the paper.

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Correspondence to Raheleh Jafari.

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Communicated by Fernando Torres.

Raheleh Jafari was in part supported by a grant from IPM (No. 900130068).

Santiago Zarzuela Armengou was supported by MTM2010-20279-C02-01.

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Jafari, R., Zarzuela Armengou, S. On monomial curves obtained by gluing. Semigroup Forum 88, 397–416 (2014). https://doi.org/10.1007/s00233-013-9536-1

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