English

The full automorphism group of $\overline{T}$

Algebraic Geometry 2017-02-28 v1 Representation Theory

Abstract

Let G\overline G be the wonderful compactification of a simple affine algebraic group GG of adjoint type defined over C.\mathbb C. Let TG{\overline T}\subset \overline G be the closure of a maximal torus TG.T\subset G. We prove that the group of all automorphisms of the variety T\overline T is the semi-direct product NG(T)D,N_G(T)\rtimes D, where NG(T)N_G(T) is the normalizer of TT in GG and DD is the group of all automorphisms of the Dynkin diagram, if GPSL(2,C)G\not= {\rm PSL}(2,\mathbb{C}). Note that if G=PSL(2,C)G = {\rm PSL}(2,\mathbb{C}), then T=CP1\overline{T} = {\mathbb C}{\mathbb P}^1 and so in this case Aut(T)=PSL(2,C)\text{Aut}(\overline T)= {\rm PSL}(2,\mathbb{C}).

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Cite

@article{arxiv.1702.08364,
  title  = {The full automorphism group of $\overline{T}$},
  author = {Indranil Biswas and Subramaniam Senthamarai Kannan and Donihakalu Shankar Nagaraj},
  journal= {arXiv preprint arXiv:1702.08364},
  year   = {2017}
}

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