Abstract
Let G be a finite group and let π : G → G′ be a surjective group homomorphism. Consider the cocycle deformation L = H σ of the Hopf algebra H = k G of k-valued linear functions on G, with respect to some convolution invertible 2-cocycle σ. The (normal) Hopf subalgebra \(k^{G'} \subseteq k^{G}\) corresponds to a Hopf subalgebra \(L' \subseteq L\). Our main result is an explicit necessary and sufficient condition for the normality of L′ in L.
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This work was partially supported by CONICET, Fundación Antorchas, Agencia Córdoba Ciencia, ANPCyT and Secyt (UNC).
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Galindo, C., Natale, S. Normal Hopf subalgebras in cocycle deformations of finite groups. manuscripta math. 125, 501–514 (2008). https://doi.org/10.1007/s00229-007-0156-5
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DOI: https://doi.org/10.1007/s00229-007-0156-5