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arXiv · 2601.22941

Compact group Rohlin actions and $G$-kernels on von Neumann algebras

Takumi Nishihara
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Abstract

We provide a new construction of a topological group model for the string group of a compact, simple, and simply-connected Lie group, by solving the obstruction realization problem for compact group $G$-kernels on full factors. Furthermore, we introduce the Rohlin property for actions and cocycle actions of compact groups in order to establish cohomology vanishing theorems.

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Takumi Nishihara. 2026-01-30. Compact group Rohlin actions and $G$-kernels on von Neumann algebras. https://arxiv.org/abs/2601.22941

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