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arXiv · 2108.01986

Induced coactions along a homomorphism of locally compact quantum groups

Kan Kitamura
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Abstract

We consider induced coactions on C*-algebras along a homomorphism of locally compact quantum groups which need not give a closed quantum subgroup. Our approach generalizes the induced coactions constructed by Vaes, and also includes certain fixed point algebras. We focus on the case when the homomorphism satisfies a quantum analogue of properness. Induced coactions along such a homomorphism still admit the natural formulations of various properties known in the case of a closed quantum subgroup, such as imprimitivity and adjointness with restriction. Also, we show a relationship of induced coactions and restriction which is analogous to base change formula for modules over algebras. As an application, we give an example that shows several kinds of 1-categories of coactions with forgetful functors cannot recover the original quantum group.

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Kan Kitamura. 2021-08-04. Induced coactions along a homomorphism of locally compact quantum groups. https://arxiv.org/abs/2108.01986

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