Abstract
A numerical semigroup is a submonoid of \({\mathbb {N}}\) with finite complement in \({\mathbb {N}}\). A generalized numerical semigroup is a submonoid of \({\mathbb {N}}^{d}\) with finite complement in \({\mathbb {N}}^{d}\). In the context of numerical semigroups, Wilf’s conjecture is a long standing open problem whose study has led to new mathematics and new ways of thinking about monoids. A natural extension of Wilf’s conjecture, to the class of \({\mathcal {C}}\)-semigroups, was proposed by García-García, Marín-Aragón, and Vigneron-Tenorio. In this paper, we propose a different generalization of Wilf’s conjecture, to the setting of generalized numerical semigroups, and prove the conjecture for several large families including the irreducible, symmetric, and monomial case. We also discuss the relationship of our conjecture to the extension proposed by García-García, Marín-Aragón, and Vigneron-Tenorio.
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References
Atiyah, M.F., Macdonald, I.G.: Introduction to Commutative Algebra. Addison-Wesley Publishing Company, Boston (1969)
Bras-Amorós, M.: The ordinarization transform of a numerical semigroup and semigroups with a large number of intervals. J. Pure Appl. Algebra 213, 2507–2518 (2012)
Cisto, C., Delgado, M., García-Sánchez, P.A.: Algorithms for Generalized Numerical Semigroups. arXiv:1907.02461 (2019)
Cisto, C., Failla, G., Utano, R.: On the generators of a generalized numerical semigroup. Analele Univ. “Ovidius” 27(1), 49–59 (2019)
Cisto, C., Failla, G., Peterson, C., Utano, R.: Irreducible generalized numerical semigroups and uniqueness of the Frobenius element. Semigroup Forum 99(2), 481–495 (2019)
Cox, D., Little, J., O’Shea, D.: Ideals, Varieties, and Algorithms, Undergraduate Texts in Mathematics. Springer, Berlin (2007)
Delgado, M.: Conjecture of Wilf: A Survey. arXiv:1902.03461 (2019)
Delgado, M., García-Sánchez, P.A., Morais, J.: NumericalSgps, A Package for Numerical Semigroups, Version 1.1.11. https://gap-packages.github.io/numericalsgps (2019). (Refereed GAP package)
Dobbs, D., Matthews, G.M.: On a question of Wilf concerning numerical semigroups. In: Badawi, A. (ed.) Focus on Commutative Rings Research, pp. 193–202. Nova Science Publishers, New York (2006)
Eliahou, S.: Wilf’s conjecture and Macaulay’s theorem. J. Eur. Math. Soc. (JEMS) 20(9), 2105–2129 (2018)
Failla, G., Peterson, C., Utano, R.: Algorithms and basic asymptotics for generalized numerical semigroups in \(\mathbb{N}^{d}\). Semigroup Forum 92(2), 460–473 (2016)
The GAP Group, GAP -- Groups, Algorithms, and Programming, Version 4.10.2. https://www.gap-system.org (2019)
García-García, J.I., Marín-Aragón, D., Vigneron-Tenorio, A.: An extension of Wilf’s conjecture to affine semigroups. Semigroup Forum 96(2), 396–408 (2018)
Hemmecke, R., Takemura, A., Yoshida, R.: Computing holes in semi-groups and its applications to transportation problems. Contrib. Discrete Math. 4(1), 81–91 (2009)
Herzog, J., Moradi, S., Rahimbeigi, M., Soleyman Jahan, A.: On the Monomial Reduction Number of a Monomial Ideal in \(K[x,y]\). arXiv:1908.03765 (2019)
Kaplan, N.: Counting numerical semigroups by genus and some cases of a question of Wilf. J. Pure Appl. Algebra 216, 1016–1032 (2012)
Rosales, J.C., García-Sánchez, P.A.: Numerical semigroups. Developments in Mathematics, vol. 20. Springer, New York (2009)
Sammartano, A.: Numerical semigroups with large embedding dimension satisfy Wilf’s conjecture. Semigroup Forum 85, 439–447 (2012)
Swanson, I., Huneke, C.: Integral Closure of Ideals, Rings, and Modules, Volume 336 of London Mathematical Society Lecture Note Series. Cambridge University Press, Cambridge (2006)
Wilf, H.S.: A circle-of-lights algorithm for the money-changing problem. Am. Math. Mon. 85, 562–565 (1978)
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Communicated by Fernando Torres.
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The research that led to the present paper was partially supported by a grant of the group GNSAGA of INdAM. DiPasquale, Peterson, and Flores would like to thank the University of Messina for its financial support. The research of DiPasquale, Peterson, and Flores was also supported in part by NSF Grant DMS-1830676.
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Cisto, C., DiPasquale, M., Failla, G. et al. A generalization of Wilf’s conjecture for generalized numerical semigroups. Semigroup Forum 101, 303–325 (2020). https://doi.org/10.1007/s00233-020-10085-7
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DOI: https://doi.org/10.1007/s00233-020-10085-7