Abstract
If X is a projective variety and G is an algebraic group acting algebraically on X, we provide a counter-example to the existence of a G-equivariant extension on the formal semi-universal deformation of X.
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References
Blanc, J.: Finite subgroups of the Cremona group of the plane. In: The 35th Autumn School in Algebraic Geometry, Poland, September 23–September 29 (2012)
Hartshorne, R.: Algebraic Geometry. Springer Verlag Graduate Texts in Mathematics, vol. 52. Springer, Berlin (1977)
Kodaira, K.: Complex Manifolds and Deformation of Complex Structures. Classics in Mathematics, English edn. Springer, Berlin (2005)
Rim, D.S.: Equivariant \(G\)-structure on versal deformations. Trans. Am. Math. Soc. 257(1), 217–226 (1980)
Schlessinger, M.: Functors of Artin rings. Trans. Am. Math. Soc. 130(2), 208–222 (1968)
Sernesi, E.: Deformations of Algebraic Schemes. Grundlehren der Mathematischen Wissenschaften, vol. 334. Springer, Berlin (2006)
Wavrik, J.J.: Obstructions to the existence of a space of moduli. Papers in Honour of K. Kodaira, pp. 403–414, Princeton University Press, Princeton (1969)
Acknowledgements
I would like to thank Prof. Bernd Siebert for many useful discussions. Actually, I learned the idea of using the extension of vector fields and their relations as obstructions to the extension of the group action from an unpublished paper of his. This provides a strategy to attack the problem. I am specially thankful to Prof. Julien Grivaux for his careful reading and his comments which help to improve the manuscript. Finally, I am warmly grateful to the referee whose work led to a remarkable improvement of the paper.
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Doan, A.K. A Counter-Example to the Equivariance Structure on Semi-universal Deformation. J Geom Anal 31, 3698–3712 (2021). https://doi.org/10.1007/s12220-020-00411-4
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DOI: https://doi.org/10.1007/s12220-020-00411-4