Home Geometric nilpotent Lie algebras and zero-dimensional simple complete intersection singularities
Article
Licensed
Unlicensed Requires Authentication

Geometric nilpotent Lie algebras and zero-dimensional simple complete intersection singularities

  • Naveed Hussain , Stephen S.-T. Yau EMAIL logo and Huaiqing Zuo
Published/Copyright: January 6, 2022

Abstract

The Levi theorem tells us that every finite-dimensional Lie algebra is the semi-direct product of a semi-simple Lie algebra and a solvable Lie algebra. Brieskorn gave the connection between simple Lie algebras and simple singularities. Simple Lie algebras have been well understood, but not the solvable (nilpotent) Lie algebras. Therefore, it is important to establish connections between singularities and solvable (nilpotent) Lie algebras. In this paper, we give a new connection between nilpotent Lie algebras and nilradicals of derivation Lie algebras of isolated complete intersection singularities. As an application, we obtain the correspondence between the nilpotent Lie algebras of dimension less than or equal to 7 and the nilradicals of derivation Lie algebras of isolated complete intersection singularities with modality less than or equal to 1. Moreover, we give a new characterization theorem for zero-dimensional simple complete intersection singularities.

MSC 2010: 14B05; 32S05

Dedicated to Professor William Fulton on the occasion of his 82th birthday



Communicated by Jan Frahm


Award Identifier / Grant number: 11961141005

Award Identifier / Grant number: 11771231

Funding statement: Both Yau and Zuo are supported by NSFC Grant 11961141005. Zuo is supported by Tsinghua University Initiative Scientific Research Program and NSFC Grant 11771231. Yau is supported by Tsinghua University start-up fund and Tsinghua University Education Foundation fund (No. 042202008). Hussain is supported by an innovation team project of Humanities and Social Sciences in Colleges and Universities of Guangdong Province (No. 2020wcxtd008).

A Appendix

Maple code description.

Query(Alg1, Alg2, parm, “Homomorphism”) returns a 4-tuple TF, Eq, Soln, B. Here TF is true if Maple finds a set of values for the parameters for which the Matrix A is a homomorphism; Eq is the defining set of equations for the parameters parm in order that the matrix A be a homomorphism; Soln is a list of solutions to the equations Eq; and B is the list of Matrices obtained by evaluating A on the solutions in the list Soln.

A.1 Maple program of Proposition 2.1

> with(DifferentialGeometry):with(LieAlgebras):>L1:=_DG([[“LieAlgebra”,Alg1,[5]],[[[1,3,2],2],[[1,4,2],-1],[[1,5,3],-1],[[1,5,4],2]>DGsetup(L1):>L2:=_DG([[“LieAlgebra”,Alg2,[5]],[[[1,2,3],1],[[1,3,4],1],[[2,5,4],1]> DGsetup(L2):> A:= Matrix([[a11, a12, a13, a14, a15], [a21, a22, a23, a24, a25], [a31, a32, a33, a34, a35], [a41, a42, a43, a44, a45], [a51, a52, a53, a54, a55]])> TF, EQ, SOLN, B:= Query(Alg1, Alg2, A, {a11, a12, a13, a14, a15, a21, a22, a23, a24, a25, a31, a32, a33, a34, a35, a41, a42, a43, a44, a45, a51, a52, a53, a54, a55}, “Homomorphism”)

A.2 Maple program of Proposition 2.1

>with(DifferentialGeometry):with(LieAlgebras):>L1:=_DG([[“LieAlgebra”,Alg3,[5]],[[[1,3,2],2],[[1,4,2],-1],[[1,5,3],-1],[[1,5,4],2]> DGsetup(L1):>L2:=_DG([[“LieAlgebra”,Alg4,[5]],[[[1,2,3],1],[[1,3,4],1],[[2,5,4],1]> DGsetup(L2, [f], [θ])>

A:=[100001000410-2111-141110001]

>ϕ:= Transformation(Alg3, Alg4, A)> Query(Alg3, Alg4, A, “Homomorphism”)> true

Acknowledgements

The authors would like to thank Craig Seeley for offering us some useful advice when we tried to construct some isomorphisms in the proof of Theorem A.

References

[1] A. G. Aleksandrov, Normal forms of one-dimensional quasihomogeneous complete intersections, Mat. Sb. (N.S.) 117(159) (1982), no. 1, 3–31. 10.1070/SM1983v045n01ABEH000989Search in Google Scholar

[2] A. G. Aleksandrov and B. Martin, Derivations and deformations of Artinian algebras, Beitr. Algebra Geom. 33 (1992), 115–130. Search in Google Scholar

[3] V. I. Arnold, S. M. Guseĭn-Zade and A. N. Varchenko, Singularities of Differentiable Maps. Vol. I, 2nd ed., MCNMO, Moscow, 2004. Search in Google Scholar

[4] C.-Y. Chao, Uncountably many nonisomorphic nilpotent Lie algebras, Proc. Amer. Math. Soc. 13 (1962), 903–906. 10.1090/S0002-9939-1962-0148715-3Search in Google Scholar

[5] B. Chen, H. Chen, S. S.-T. Yau and H. Zuo, The nonexistence of negative weight derivations on positive dimensional isolated singularities: Generalized Wahl conjecture, J. Differential Geom. 115 (2020), no. 2, 195–224. 10.4310/jdg/1589853625Search in Google Scholar

[6] B. Chen, N. Hussain, S. S.-T. Yau and H. Zuo, Variation of complex structures and variation of Lie algebras II: New Lie algebras arising from singularities, J. Differential Geom. 115 (2020), no. 3, 437–473. 10.4310/jdg/1594260016Search in Google Scholar

[7] H. Chen, S. S.-T. Yau and H. Zuo, Non-existence of negative weight derivations on positively graded Artinian algebras, Trans. Amer. Math. Soc. 372 (2019), no. 4, 2493–2535. 10.1090/tran/7628Search in Google Scholar

[8] A. H. Durfee, Fifteen characterizations of rational double points and simple critical points, Enseign. Math. (2) 25 (1979), no. 1–2, 131–163. Search in Google Scholar

[9] A. Elashvili and G. Khimshiashvili, Lie algebras of simple hypersurface singularities, J. Lie Theory 16 (2006), no. 4, 621–649. Search in Google Scholar

[10] M. Gauger, On the classification of metabelian Lie algebras, Trans. Amer. Math. Soc. 179 (1973), 293–329. 10.1090/S0002-9947-1973-0325719-0Search in Google Scholar

[11] M. Giusti, Classification des singularités isolées d’intersections complètes simples, C. R. Acad. Sci. Paris Sér. A-B 284 (1977), no. 3, A167–A170. 10.1090/pspum/040.1/713086Search in Google Scholar

[12] J. E. Humphreys, Introduction to Lie Algebras and Representation Theory, Grad. Texts in Math. 9, Springer, New York, 1972. 10.1007/978-1-4612-6398-2Search in Google Scholar

[13] N. Hussain, Survey on derivation Lie algebras of isolated singularities, Methods Appl. Anal. 25 (2018), no. 4, 307–322. 10.4310/MAA.2018.v25.n4.a3Search in Google Scholar

[14] N. Hussain, S. S.-T. Yau and H. Zuo, On the derivation Lie algebras of fewnomial singularities, Bull. Aust. Math. Soc. 98 (2018), no. 1, 77–88. 10.1017/S0004972718000266Search in Google Scholar

[15] N. Hussain, S. S.-T. Yau and H. Zuo, Generalized Cartan matrices arising from new derivation Lie algebras of isolated hypersurface singularities, Pacific J. Math. 305 (2020), no. 1, 189–217. 10.2140/pjm.2020.305.189Search in Google Scholar

[16] N. Hussain, S. S.-T. Yau and H. Zuo, On the new k-th Yau algebras of isolated hypersurface singularities, Math. Z. 294 (2020), no. 1–2, 331–358. 10.1007/s00209-019-02269-xSearch in Google Scholar

[17] N. Hussain, S. S.-T. Yau and H. Zuo, Inequality conjectures on derivations of local k-th Hessain algebras associated to isolated hypersurface singularities, Math. Z. 298 (2021), no. 3–4, 1813–1829. 10.1007/s00209-020-02688-1Search in Google Scholar

[18] N. Hussain, S. S.-T. Yau and H. Zuo, kth Yau number of isolated hypersurface singularities and an inequality conjecture, J. Aust. Math. Soc. 110 (2021), no. 1, 94–118. 10.1017/S1446788719000132Search in Google Scholar

[19] N. Hussain, S. S.-T. Yau and H. Zuo, On the generalized Cartan matrices arising from k-th Yau algebras of isolated hypersurface singularities, Algebr. Represent. Theory 24 (2021), no. 4, 1101–1124. 10.1007/s10468-020-09981-xSearch in Google Scholar

[20] N. Hussain, S. S.-T. Yau and H. Zuo, On two inequality conjectures for the k-th Yau numbers of isolated hypersurface singularities, Geom. Dedicata 212 (2021), 57–71. 10.1007/s10711-020-00549-zSearch in Google Scholar

[21] N. Hussain, S. S.-T. Yau and H. Zuo, Classification of the nilpotent of k-th Yau algebras arising from singularities, to appear. Search in Google Scholar

[22] N. Hussain, S. S.-T. Yau and H. Zuo, New k-th Yau algebras of isolated hypersurface singularities and weak Torelli-type theorem, Math. Res. Lett., to appear. 10.4310/MRL.2022.v29.n2.a7Search in Google Scholar

[23] N. Hussain, S. S.-T. Yau and H. Zuo, On derivation Lie algebras of isolated complete intersection singularities, to appear. Search in Google Scholar

[24] N. Jacobson, Lie Algebras, Intersci. Tracts Pure Appl. Math. 10, Interscience, New York, 1962. Search in Google Scholar

[25] G. Khimshiashvili, Yau algebras of fewnomial singularities, preprint, http://www.math.uu.nl/publications/preprints/1352.pdf. Search in Google Scholar

[26] G. Ma, S. S.-T. Yau and H. Zuo, On the non-existence of negative weight derivations of the new moduli algebras of singularities, J. Algebra 564 (2020), 199–246. 10.1016/j.jalgebra.2020.07.023Search in Google Scholar

[27] L. Magnin, Sur les algèbres de Lie nilpotentes de dimension 7, J. Geom. Phys. 3 (1986), no. 1, 119–144. 10.1016/0393-0440(86)90005-7Search in Google Scholar

[28] J. N. Mather and S. S. T. Yau, Classification of isolated hypersurface singularities by their moduli algebras, Invent. Math. 69 (1982), no. 2, 243–251. 10.1007/BF01399504Search in Google Scholar

[29] V. V. Morozov, Classification of nilpotent Lie algebras of sixth order, Izv. Vyssh. Uchebn. Zaved. Mat. 4 (1958), no. 5, 161–171. Search in Google Scholar

[30] E. N. Safiullina, Classification of nilpotent Lie algebras of order 7, Candidates’ Works (1964), Math., Mech. Phys., Izdat. Kazan. University, Kazan (1964), 66–69. Search in Google Scholar

[31] L. J. Santharoubane, Infinite families of nilpotent Lie algebras, J. Math. Soc. Japan 35 (1983), no. 3, 515–519. 10.2969/jmsj/03530515Search in Google Scholar

[32] C. Seeley, 7-dimensional nilpotent Lie algebras, Trans. Amer. Math. Soc. 335 (1993), no. 2, 479–496. 10.1090/S0002-9947-1993-1068933-4Search in Google Scholar

[33] C. Seeley and S. S.-T. Yau, Variation of complex structures and variation of Lie algebras, Invent. Math. 99 (1990), no. 3, 545–565. 10.1007/BF01234430Search in Google Scholar

[34] K. A. Umlauf, Über die Zusammensetzung der endlichen continuierlichen Transformationsgruppen, insbesondre der Gruppen vom Range null, Thesis, University of Leipzig, 1891. Search in Google Scholar

[35] C. T. C. Wall, Classification of unimodal isolated singularities of complete intersections, Singularities. Part 2 (Arcata 1981), Proc. Sympos. Pure Math. 40, American Mathematical Society, Providence (1983), 625–640. 10.1090/pspum/040.2/713286Search in Google Scholar

[36] Y.-J. Xu and S. S.-T. Yau, Micro-local characterization of quasi-homogeneous singularities, Amer. J. Math. 118 (1996), no. 2, 389–399. 10.1353/ajm.1996.0020Search in Google Scholar

[37] S. S. T. Yau, Continuous family of finite-dimensional representations of a solvable Lie algebra arising from singularities, Proc. Natl. Acad. Sci. USA 80 (1983), 7694–7696. 10.1073/pnas.80.24.7694Search in Google Scholar PubMed PubMed Central

[38] S. S.-T. Yau, Solvable Lie algebras and generalized Cartan matrices arising from isolated singularities, Math. Z. 191 (1986), no. 4, 489–506. 10.1007/BF01162338Search in Google Scholar

[39] S. S.-T. Yau, Solvability of Lie algebras arising from isolated singularities and nonisolatedness of singularities defined by sl(2,𝐂) invariant polynomials, Amer. J. Math. 113 (1991), no. 5, 773–778. 10.2307/2374785Search in Google Scholar

[40] S. S.-T. Yau and H. Zuo, Derivations of the moduli algebras of weighted homogeneous hypersurface singularities, J. Algebra 457 (2016), 18–25. 10.1016/j.jalgebra.2016.03.003Search in Google Scholar

[41] S. S.-T. Yau and H. Q. Zuo, A sharp upper estimate conjecture for the Yau number of a weighted homogeneous isolated hypersurface singularity, Pure Appl. Math. Q. 12 (2016), no. 1, 165–181. 10.4310/PAMQ.2016.v12.n1.a6Search in Google Scholar

[42] Y. Yu, On Jacobian ideals invariant by reducible sl(2;C) action, Trans. Amer. Math. Soc. 348 (1996), 2759–2791. 10.1090/S0002-9947-96-01633-9Search in Google Scholar

Received: 2021-09-04
Revised: 2021-11-25
Published Online: 2022-01-06
Published in Print: 2022-03-01

© 2022 Walter de Gruyter GmbH, Berlin/Boston

Downloaded on 9.9.2025 from https://www.degruyterbrill.com/document/doi/10.1515/forum-2021-0227/html
Scroll to top button