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Nearly Gorenstein cyclic quotient singularities. (English) Zbl 1481.13012

In the paper under review, the authors classify nearly Gorenstein rings for the invariant ring \(R^G\) where \(R=\Bbbk[[ x_1,\dotsc,x_d]]\) is a formal power series ring over an algebraically closed field \(\Bbbk,\) \(G\) is a finite cyclic subgroup of \(\mathrm{GL}(d,\Bbbk)\) acting linearly on \(R\), and \(|G|\) is invertible in \(\Bbbk.\) Since \(G\) is cyclic, the invariant ring is monomial, hence the classification can be described in terms of a numerical criterion.
Nearly Gorenstein property extends the property of being Gorenstein and the authors also provide a family of examples where nearly Gorenstein property fails by defining the residue of the trace ideal of the corresponding canonical module.
Moreover, the authors provide an exhaustive list of cyclic quotient singularities for \(d=3\) and \(4\le |G|\le 7\) and for \(d=4\) and \(4\le |G|\le 6.\) The cases where \(d=2\) or \(|G|\le3\) are already covered by their main result.
Finally, the paper contains an addendum to Ding’s classification of nearly Gorenstein quotient singularities when \(d=2.\)

MSC:

13A50 Actions of groups on commutative rings; invariant theory
13H10 Special types (Cohen-Macaulay, Gorenstein, Buchsbaum, etc.)
14L30 Group actions on varieties or schemes (quotients)

References:

[1] Barucci, V.; Fröberg, R., One-dimensional almost Gorenstein rings, J. Algebra, 188, 2, 418-442 (1997) · Zbl 0874.13018 · doi:10.1006/jabr.1996.6837
[2] Bass, H., On the ubiquity of Gorenstein rings, Math. Z., 82, 8-28 (1963) · Zbl 0112.26604 · doi:10.1007/BF01112819
[3] Beauville, A.: Finite subgroups of \(PGL_2(K)\), Vector bundles and complex geometry, 23-29, Contemp. Math. 522, Am. Math. Soc., Providence, RI, (2010) · Zbl 1218.20030
[4] Brieskorn, E., Rationale Singularitäten komplexer Flächen, Invent. Math., 4, 5, 336-358 (1968) · Zbl 0219.14003 · doi:10.1007/BF01425318
[5] Bruns, W., Herzog, J.: Cohen-Macaulay rings. Revised edition, Cambridge Studies in Advanced Mathematics, vol. 39, Cambridge University Press, (1998) · Zbl 0909.13005
[6] Dao, H., Kobayashi, T. , Takahashi, R.: Trace of canonical modules, annihilator of Ext, and classes of rings close to being Gorenstein, arXiv:2005.02263 · Zbl 1471.13034
[7] Ding, S., A note on the index of Cohen-Macaulay local rings, Commun. Algebra, 21, 1, 53-71 (1993) · Zbl 0766.13003 · doi:10.1080/00927879208824550
[8] Campbell, H.E.A., Wehlau, D.: Modular invariant theory, encyclopaedia of mathematical sciences vol. 139, Springer, Berlin Heidelberg, (2011) · Zbl 1216.14001
[9] Endo, N., Goto, S., Isobe, R.: Almost Gorenstein rings arising from fiber products, Can. Math. Bull. (to appear) · Zbl 1473.13024
[10] Goto, S.; Matsuoka, N.; Phuong, TT, Almost Gorenstein rings, J. Algebra, 379, 355-381 (2013) · Zbl 1279.13035 · doi:10.1016/j.jalgebra.2013.01.025
[11] Goto, S.; Takahashi, R.; Taniguchi, N., Almost Gorenstein rings-towards a theory of higher dimension, J. Pure Appl. Algebra, 219, 7, 2666-2712 (2015) · Zbl 1319.13017 · doi:10.1016/j.jpaa.2014.09.022
[12] Goto, S.; Takahashi, R.; Taniguchi, N., Ulrich ideals and almost Gorenstein rings, Proc. Am. Math. Soc., 144, 2811-2823 (2016) · Zbl 1338.13043 · doi:10.1090/proc/12970
[13] Herzog, J., Jafari, R., Stamate, D. I.: Ulrich elements in normal simplicial affine semigroups arXiv:1909.06846 · Zbl 1458.05268
[14] Herzog, J.; Hibi, T.; Stamate, DI, The trace of the canonical module, Isr. J. Math., 233, 133-165 (2019) · Zbl 1428.13037 · doi:10.1007/s11856-019-1898-y
[15] Hochster, M.; Eagon, JA, Cohen-Macaulay rings, invariant theory, and the generic perfection of determinantal loci, Am. J. Math., 93, 1020-1058 (1971) · Zbl 0244.13012 · doi:10.2307/2373744
[16] Huneke, C.: Hyman Bass and ubiquity: Gorenstein rings. Algebra, K-theory, groups, and education (New York, 1997), 55-78, Contemp. Math. 243, Am. Math. Soc., Providence, RI, (1999) · Zbl 0960.13008
[17] Huneke, C.; Vraciu, A., Rings that are almost Gorenstein, Pacific J. Math., 225, 85-102 (2006) · Zbl 1148.13005 · doi:10.2140/pjm.2006.225.85
[18] Kemper, G., On the Cohen-Macaulay Property of modular invariant rings, J. Algebra, 215, 1, 330-351 (1999) · Zbl 0934.13003 · doi:10.1006/jabr.1998.7716
[19] Klein, F., Vorlesungen über das Ikosaeder und die Auflösung der Gleichungen vom fünften Grade (1884), Leipzig: Teubner, Leipzig · JFM 16.0061.01
[20] Kobayashi, T.: Local rings with self-dual maximal ideal arXiv:1812.10341 · Zbl 1451.13039
[21] Kreuzer, M.; Linh, TNK; Long, N., The dedekind different of a Cayley-Bacharach scheme, J. Algebra Appl., 18, 2, 1950027 (2019) · Zbl 1507.14067 · doi:10.1142/S0219498819500270
[22] Kumashiro, S.: Almost reduction number of canonical ideals arXiv:2007.00377 · Zbl 1481.13031
[23] Leuschke, G., Wiegand, R.: Cohen-Macaulay representations. Mathematical surveys and monographs 181. American Mathematical Society, Providence (2012) · Zbl 1252.13001
[24] Moscariello, A., Strazzanti, F.: Nearly Gorenstein vs almost Gorenstein affine monomial curves. Mediterr. J. Math. arXiv:2003.05391 · Zbl 1468.13056
[25] Prill, D., Local classification of quotients of complex manifolds by discontinuous groups, Duke Math. J., 34, 375-386 (1967) · Zbl 0179.12301 · doi:10.1215/S0012-7094-67-03441-2
[26] Rahimi, M.: Rings with canonical reductions. Bull. Iranian Math. Soc. (to appear) · Zbl 1453.13069
[27] Riemenschneider, O., Die Invarianten der endlichen Untergruppen von \(GL(2,\mathbb{C})\), Math. Z., 153, 37-50 (1977) · Zbl 0336.32012 · doi:10.1007/BF01214732
[28] Singh, B., Invariants of finite groups acting on local unique factorization domains, J. Indian Math. Soc., 34, 31-38 (1970) · Zbl 0222.13020
[29] Stanley, R.P.: Hilbert functions of graded algebras. Adv. Math. 28(1), 57-83 (1978) · Zbl 0384.13012
[30] Striuli, J., Vraciu, A.: Some homological properties of almost Gorenstein rings, Commutative algebra and its connections to geometry, 201-215, Contemp. Math., 555, Am. Math. Soc., Providence, RI, (2011) · Zbl 1234.13015
[31] Taniguchi, N., On the almost Gorenstein property of determinantal rings, Comm. Algebra, 46, 1165-1178 (2018) · Zbl 1400.13025 · doi:10.1080/00927872.2017.1339066
[32] Watanabe, K., Certain invariant subrings are Gorenstein I, Osaka J. Math., 11, 1, 1-8 (1974) · Zbl 0281.13007
[33] Watanabe, K., Certain invariant subrings are Gorenstein II, Osaka J. Math., 11, 2, 379-388 (1974) · Zbl 0292.13008
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