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arXiv · 2607.28181

Consistent symmetry breaking and topological phases

Yuezhao Li·Guo Chuan Thiang
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Abstract

Operators invariant under a symmetry group are also invariant under any finite-index subgroup. The equivariant indices of such operators must be consistent under symmetry breaking. We use this principle to establish a canonical weak/strong dichotomy for equivariant indices, building on an idea originating in the theory of topological insulators in solid-state physics. We also study the relationship to coarse-geometric, or macroscopic, indices.

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Yuezhao Li, Guo Chuan Thiang. 2026-07-30. Consistent symmetry breaking and topological phases. https://arxiv.org/abs/2607.28181

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