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On reduction numbers and Castelnuovo–Mumford regularity of blowup rings and modules

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Abstract

We prove new results on the interplay between reduction numbers and the Castelnuovo–Mumford regularity of blowup algebras and blowup modules, the key basic tool being the operation of Ratliff–Rush closure. First, we answer in two particular cases a question of M. E. Rossi, D. T. Trung, and N. V. Trung about Rees algebras of ideals in two-dimensional Buchsbaum local rings, and we even ask whether one of such situations always holds. In another theorem we largely generalize a result of A. Mafi on ideals in two-dimensional Cohen–Macaulay local rings, by extending it to arbitrary dimension (and allowing for the setting relative to a Cohen–Macaulay module). We derive a number of applications, including a characterization of (polynomial) ideals of linear type, progress on the theory of generalized Ulrich ideals, and improvements of results by other authors.

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References

  1. Aberbach, I.M., Huneke, C., Trung, N.V.: Reduction numbers, Briançon–Skoda theorems and the depth of Rees rings. Compos. Math. 97, 403–434 (1995)

    Google Scholar 

  2. Bayer, D., Stillman, M.: On the complexity of computing syzygies. J. Symb. Comput. 6, 135–147 (1988)

    Article  MathSciNet  Google Scholar 

  3. Brodmann, M., Linh, C.H.: Castelnuovo–Mumford regularity, postulation numbers and relation types. J. Algebra 419, 124–140 (2014)

    Article  MathSciNet  Google Scholar 

  4. Brodmann, M., Sharp, R.: Local Cohomology: An Algebraic Introduction with Geometric Applications. Cambridge University Press, Cambridge (1998)

    Book  Google Scholar 

  5. Corso, A., Polini, C., Rossi, M.E.: Depth of associated graded rings via Hilbert coefficients of ideals. J. Pure Appl. Algebra 201, 126–141 (2005)

    Article  MathSciNet  Google Scholar 

  6. Dung, L.X., Hoa, L.T.: Castelnuovo–Mumford regularity of associated graded modules and fiber cones of filtered modules. Commun. Algebra 40, 404–422 (2012)

    Article  MathSciNet  Google Scholar 

  7. Eisenbud, D., Goto, S.: Linear free resolutions and minimal multiplicity. J. Algebra 8(8), 89–133 (1984)

    Article  MathSciNet  Google Scholar 

  8. Giral, J.M., Planas-Vilanova, F.: Integral degree of a ring, reduction numbers and uniform Artin–Rees numbers. J. Algebra 319, 3398–3418 (2008)

    Article  MathSciNet  Google Scholar 

  9. Goto, S., Ozeki, K., Takahashi, R., Watanabe, K.I., Yoshida, K.I.: Ulrich ideals and modules. Math. Proc. Camb. Philos. Soc. 156, 137–166 (2014)

    Article  MathSciNet  Google Scholar 

  10. Goto, S., Ozeki, K., Takahashi, R., Watanabe, K.-I., Yoshida, K.-I.: Ulrich ideals and modules over two-dimensional rational singularities. Nagoya Math. J. 221, 69–110 (2016)

    Article  MathSciNet  Google Scholar 

  11. Heinzer, W., Johnston, B., Lantz, D., Shah, K.: The Ratliff–Rush ideals in a Noetherian ring: a survey. In: Methods in Module Theory, Colorado Springs, CO, 1991, in: Lecture Notes in Pure and Applied Mathematics, vol. 140, pp. 149–159. Dekker, New York (1992)

  12. Heinzer, W., Lantz, D., Shah, K.: The Ratliff–Rush ideals in a Noetherian ring. Commun. Algebra 20, 591–622 (1992)

    Article  MathSciNet  Google Scholar 

  13. Herzog, J., Popescu, D., Trung, N.V.: Regularity of Rees algebras. J. Lond. Math. Soc. 65, 320–338 (2002)

    Article  MathSciNet  Google Scholar 

  14. Hoa, L.T.: A note on the Hilbert function in a two-dimensional local ring. Acta Math. Vietnam 21, 335–347 (1996)

    MathSciNet  Google Scholar 

  15. Huckaba, S.: Reduction numbers for ideals of higher analytic spread. Math. Proc. Camb. Philos. Soc. 102, 49–57 (1987)

    Article  MathSciNet  Google Scholar 

  16. Huneke, C.: Hilbert functions and symbolic powers. Michigan Math. J. 34, 293–318 (1987)

    Article  MathSciNet  Google Scholar 

  17. Itoh, S.: Hilbert coefficients of integrally closed ideals. J. Algebra 176, 638–652 (1995)

    Article  MathSciNet  Google Scholar 

  18. Johnson, M., Ulrich, B.: Artin-Nagata properties and Cohen–Macaulay associated graded rings. Compos. Math. 108, 7–29 (1996)

    MathSciNet  Google Scholar 

  19. Linh, C.H.: Upper bound for the Castelnuovo–Mumford regularity of associated graded modules. Commun. Algebra 33, 1817–1831 (2005)

    Article  MathSciNet  Google Scholar 

  20. Lipman, J.: Rational singularities with applications to algebraic surfaces and unique factorization. Inst. Hautes Études Sci. Publ. Math. 36, 195–279 (1969)

    Article  MathSciNet  Google Scholar 

  21. Mafi, A.: On the computation of the Ratliff–Rush closure, associated graded ring and invariance of a length. J. Commun. Algebra 10, 547–557 (2018)

    MathSciNet  Google Scholar 

  22. Mafi, A.: Ratliff–Rush ideal and reduction numbers. Commun. Algebra 46, 1272–1276 (2018)

    Article  MathSciNet  Google Scholar 

  23. Marley, T.: The coefficients of the Hilbert polynomial and the reduction number of an ideal. J. Lond. Math. Soc. 40, 1–8 (1989)

    Article  MathSciNet  Google Scholar 

  24. Marley, T.: The reduction number of an ideal and the local cohomology of the associated graded ring. Proc. Am. Math. Soc. 117, 335–341 (1993)

    Article  MathSciNet  Google Scholar 

  25. Naghipour, R.: Ratliff-Rush closures of ideals with respect to a Noetherian module. J. Pure Appl. Algebra 195, 167–172 (2005)

    Article  MathSciNet  Google Scholar 

  26. Northcott, D.G., Rees, D.: Reductions of ideals in local rings. Math. Proc. Camb. Philos. Soc. 50, 145–158 (1954)

    Article  ADS  MathSciNet  Google Scholar 

  27. Ooishi, A.: Genera and arithmetic genera of commutative rings. Hiroshima Math. J. 17, 47–66 (1987)

    MathSciNet  Google Scholar 

  28. Polini, C., Xie, Y.: \(j\)-Multiplicity and depth of associated graded modules. J. Algebra 379, 31–49 (2013)

    Article  MathSciNet  Google Scholar 

  29. Puthenpurakal, T.J.: Ratliff–Rush filtration, regularity and depth of higher associated graded modules: part I. J. Pure Appl. Algebra 208, 159–176 (2007)

    Article  MathSciNet  Google Scholar 

  30. Ratliff, L.J., Rush, D.E.: Two notes on reductions of ideals. Indiana Univ. Math. J. 27, 929–934 (1978)

    Article  MathSciNet  Google Scholar 

  31. Rossi, M.E., Trung, D.T., Trung, N.V.: Castelnuovo–Mumford regularity and Ratliff–Rush closure. J. Algebra 504, 568–586 (2018)

    Article  MathSciNet  Google Scholar 

  32. Rossi, M.E., Trung, N.V., Valla, G.: Castelnuovo–Mumford regularity and extended degree. Trans. Am. Math. Soc. 355, 1773–1786 (2003)

    Article  MathSciNet  Google Scholar 

  33. Rossi, M.E., Valla, G.: Hilbert Functions of Filtered Modules, UMI Lecture Notes 9. Springer, New York (2010)

    Google Scholar 

  34. Sally, J.D.: Reductions, local cohomology and Hilbert functions of local rings. In: Commutative Algebra: Durham 1981: London Mathematical Society Lecture Note series, vol. 72, pp 231–241. Cambridge University Press, Cambridge (1982)

  35. Strunk, B.: Castelnuovo–Mumford regularity, postulation numbers, and reduction numbers. J. Algebra 311, 538–550 (2007)

    Article  MathSciNet  Google Scholar 

  36. Swanson, I., Huneke, C.: Integral Closure of Ideals, Rings, and Modules. Cambridge University Press, Cambridge (2006)

    Google Scholar 

  37. Trung, D.T.: On the computation of Castelnuovo–Mumford regularity of the Rees algebra and of the fiber ring. J. Pure Appl. Algebra 224, 402–410 (2020)

    Article  MathSciNet  Google Scholar 

  38. Trung, N.V.: The Castelnuovo regularity of the Rees algebra and the associated graded ring. Trans. Am. Math. Soc. 350, 2813–2832 (1998)

    Article  ADS  MathSciNet  Google Scholar 

  39. Trung, N.V.: Castelnuovo–Mumford regularity and related invariants. In: Commutative Algebra, Lecture Notes Series, vol. 4, pp. 157–180. Ramanujan Mathematical Society (2007)

  40. Valla, G.: On form rings which are Cohen–Macaulay. J. Algebra 58, 247–250 (1979)

    Article  MathSciNet  Google Scholar 

  41. Vasconcelos, W.V.: Multiplicities and reduction numbers. Compos. Math. 139, 361–379 (2003)

    Article  MathSciNet  Google Scholar 

  42. Wu, Y.: Reduction numbers and Hilbert polynomials of ideals in higher-dimensional Cohen–Macaulay local rings. Math. Proc. Camb. Philos. Soc. 111, 47–56 (1992)

    Article  MathSciNet  Google Scholar 

  43. Zamani, N.: A formula for reduction number of an ideal relative to a Noetherian module. Int. Electron. J. Algebra 5, 114–120 (2009)

    ADS  MathSciNet  Google Scholar 

  44. Zamani, N.: Regularity of the Rees and associated graded modules. Eur. J. Pure Appl. Math. 7, 429–436 (2014)

    MathSciNet  Google Scholar 

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Acknowledgements

The first author was partially supported by CNPq (grants 301029/2019-9 and 406377/2021-9). The second author was supported by a CAPES Doctoral Scholarship. They are grateful to the anonymous reviewers for a careful reading of the manuscript and helpful suggestions, including an improvement in Corollary 5.1.

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Correspondence to Cleto B. Miranda-Neto.

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Dedicated to the memory of Professor Wolmer Vasconcelos, mentor of generations of commutative algebraists.

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Miranda-Neto, C.B., Queiroz, D.S. On reduction numbers and Castelnuovo–Mumford regularity of blowup rings and modules. Collect. Math. (2024). https://doi.org/10.1007/s13348-024-00436-w

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