Abstract
We describe the centers of the universal enveloping algebras of nilpotent Lie algebras of dimension at most six over fields of prime characteristic. If the characteristic is not smaller than the nilpontency class, then the center is the integral closure of the algebra generated over the p-center by the same generators that also occur in characteristic zero. Except for three examples, two of which are standard filiform, this algebra is already integrally closed and hence it coincides with the center. In the case of these three exceptional algebras, the center has further generators. Then we show that the center of the universal enveloping algebra of the algebras investigated in this paper is isomorphic to the Poisson center (the algebra of invariants under the adjoint representation). This shows that Braun’s conjecture is valid for this class of Lie algebras.
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References
Braun, Amiram: Factorial properties of the enveloping algebra of a nilpotent Lie algebra in prime characteristic. J. Algebra 308(1), 1–11 (2007)
Braun, A.: The center of the enveloping algebra of the \(p\)-Lie algebras \({{{\mathfrak{s}}}}{{{\mathfrak{l}}}}_n\), \(\mathfrak{pgl}_n\), \(\mathfrak{psl}_n\), when \(p\) divides \(n\). J. Algebra 504, 217–290 (2018)
Ben-Shimol, O.: On Dixmier-Duflo isomorphism in positive characteristic-the classical nilpotent case. J. Algebra 382, 203–239 (2013)
Braun, A., Vernik, G.: On the center and semi-center of enveloping algebras in prime characteristic. J. Algebra 322(5), 1830–1858 (2009)
Cicalò, S., de Graaf, W.A., Schneider, C.: Six-dimensional nilpotent Lie algebras. Linear Algebra Appl. 436(1), 163–189 (2012)
Cicalò, S., de Graaf, W.A., Schneider, C.: Corrigendum to “Six-dimensional nilpotent Lie algebras” [Linear Algebra Appl. 436 (2012) 163–189]. Linear Algebra Appl. 604, 507–508 (2020)
de Graaf, W.A.: Classification of 6-dimensional nilpotent Lie algebras over fields of characteristic not 2. J. Algebra 309(2), 640–653 (2007)
de Jesus, V.L.: O centro das álgebras envolventes universais de álgebras de Lie nilpotentes em característica prima. PhD thesis, Universidade Federal de Minas Gerais (2021). https://repositorio.ufmg.br/handle/1843/39048
Dixmier, J.: Enveloping algebras. In: Graduate Studies in Mathematics, vol. 11. American Mathematical Society, Providence (1996) (revised reprint of the 1977 translation)
Drozd, Y.A., Kirichenko, V.V.: Finite-dimensional algebras. Springer-Verlag, Berlin, (1994). Translated from the 1980 Russian original and with an appendix by Vlastimil Dlab
Duflo, M.: Opérateurs différentiels bi-invariants sur un groupe de Lie. Ann. Sci. École Norm. Sup. (4) 10(2), 265–288 (1977)
Grayson, D.R., Stillman, M.E.: Macaulay2, a software system for research in algebraic geometry. http://www.math.uiuc.edu/Macaulay2/
Isaacs, I.M.: Algebra: a graduate course. In: Graduate Studies in Mathematics, vol. 100. American Mathematical Society, Providence (2009) (reprint of the 1994 original)
Kemper, G.: A course in commutative algebra. In: Graduate Texts in Mathematics, vol. 256. Springer, Heidelberg (2011)
Kontsevich, M.: Deformation quantization of Poisson manifolds. Lett. Math. Phys. 66(3), 157–216 (2003)
Lang, S.: Algebra. In: Graduate Texts in Mathematics, vol. 211, 3rd edn. Springer, New York (2002)
Matsumura, H.: Commutative ring theory. In: Cambridge Studies in Advanced Mathematics, vol. 8, 2nd edn. Cambridge University Press, Cambridge (1989) (translated from the Japanese by M. Reid)
Ooms, A.I.: Computing invariants and semi-invariants by means of Frobenius Lie algebras. J. Algebra 321(4), 1293–1312 (2009)
Ooms, A.I.: The Poisson center and polynomial, maximal Poisson commutative subalgebras, especially for nilpotent Lie algebras of dimension at most seven. J. Algebra 365, 83–113 (2012)
Strade, H., Farnsteiner, R: Modular Lie algebras and their representations. In: Monographs and Textbooks in Pure and Applied Mathematics, vol. 116. Marcel Dekker Inc, New York (1988)
Singh, A.K., Swanson, I.: An algorithm for computing the integral closure. Algebra Number Theory 3(5), 587–595 (2009)
Vasconcelos, W.: Rees algebras, multiplicities, algorithms. In: Integral Closure. Springer Monographs in Mathematics. Springer, Berlin (2005)
Šnobl, L., Winternitz, P.: Classification and identification of Lie algebras. In: CRM Monograph Series, vol. 33. American Mathematical Society, Providence (2014)
Zassenhaus, H.: The representations of Lie algebras of prime characteristic. Proc. Glasgow Math. Assoc. 2, 1–36 (1954)
Acknowledgements
Vanderlei Lopes de Jesus was financially supported by a PhD scholarship awarded by CNPq (Brazil). Csaba Schneider acknowledges the financial support of the CNPq projects Produtividade em Pesquisa (project no.: 308212/2019-3) and Universal (project no.: 421624/2018-3). We thank Lucas Calixto, Letterio Gatto, Tiago Macedo, and Renato Vidal Martins for their valuable comments. We also thank the anonymous referee for his or her useful suggestions.
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de Jesus, V.L., Schneider, C. The center of the universal enveloping algebras of small-dimensional nilpotent Lie algebras in prime characteristic. Beitr Algebra Geom 64, 243–266 (2023). https://doi.org/10.1007/s13366-022-00631-5
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DOI: https://doi.org/10.1007/s13366-022-00631-5
Keywords
- Lie algebras
- Nilpotent Lie algebras
- Universal enveloping algebras
- Center
- Poisson center
- Invariant ring
- Poincaré–Birkhoff–Witt Theorem