English

sl(n,H)-Current Algebra on S^3

Differential Geometry 2018-07-12 v3 Mathematical Physics math.MP Representation Theory

Abstract

We introduce three non-trivial 2-cocycles ckc_k, k=0,1,2, on the Lie algebra S3H=Map(S3,H)S^3H=Map(S^3,H) with the aid of the corresponding basis vector fields on S3S^3, and extend them to 2-cocycles on the Lie algebra S3gl(n,H)=S3Hgl(n,C)S^3gl(n,H)=S^3H \otimes gl(n,C). Then we have the corresponding central extension S3gl(n,H)k(Cak)S^3gl(n,H)\oplus \oplus_k (Ca_k). As a subalgebra of S3HS^3H we have the algebra C[ϕ]C[\phi] of the Laurent polynomial spinors on S3S^3. Then we have a Lie subalgebra gl^(n,H)=C[ϕ]gl(n,C)\hat{gl}(n, H)=C[\phi] \otimes gl(n, C) of S3gl(n,H)S^3gl(n,H), as well as its central extension by the 2-cocycles ck{c_k} and the Euler vector field dd: gl^=gl^(n,H)k(Cak)Cd\hat{gl}=\hat{gl}(n, H) \oplus \oplus_k(Ca_k)\oplus Cd . The Lie algebra sl^(n,H)\hat{sl}(n,H) is defined as a Lie subalgebra of gl^(n,H)\hat{gl}(n,H) generated by C[ϕ]sl(n,C))C[\phi]\otimes sl(n,C)). We have the corresponding central extension of sl^(n,H)\hat{sl}(n,H) by the 2-cocycles ck{c_k} and the derivation dd, which becomes a Lie subalgebra sl^\hat{sl} of gl^\hat{gl}. Let h0h_0 be a Cartan subalgebra of sl(n,C)sl(n,C) and h^=h0k(Cak)Cd\hat{h}=h_0 \oplus \oplus_k(Ca_k)\oplus Cd. The root space decomposition of the ad(h^)ad(\hat{h})-representation of sl^\hat{sl} is obtained. The set of roots is Δ={m/2δ+α;αΔ0,mZ}{m/2δ;mZ}\Delta =\{ m/2 \delta + \alpha ; \alpha \in \Delta_0, m \in Z\} \bigcup \{m/2 \delta ; m \in Z \} . And the root spaces are g^m/2δ+α=C[ϕ;m]gα\hat{g}_{m/2 \delta+ \alpha}= C[\phi ;m] \otimes g_{\alpha}, for α0\alpha\neq 0 , g^m/2δ=C[ϕ;m]h0\hat{g}_{m/2 \delta}= C[\phi ;m] \otimes h_0, for m0m \neq 0, and g^0δ=h^\hat{g}_{0 \delta}= \hat{h}, where C[ϕ;m]C[\phi ;m] is the subspace with the homogeneous degree m. The Chevalley generators of sl^\hat{sl} are given.

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Cite

@article{arxiv.1710.09712,
  title  = {sl(n,H)-Current Algebra on S^3},
  author = {Tosiaki Kori},
  journal= {arXiv preprint arXiv:1710.09712},
  year   = {2018}
}

Comments

arXiv admin note: text overlap with arXiv:1306.5030

R2 v1 2026-06-22T22:26:37.451Z