dorsal/arxiv
View SchemaOn the structure of Witt groups and minimal extension conjecture
| Authors | Theo Johnson-Freyd, Victor Ostrik, Zhiqiang Yu |
|---|---|
| Categories | |
| ArXiv ID | 2601.09060vv1 |
| URL | https://arxiv.org/abs/2601.09060 |
| License | http://creativecommons.org/publicdomain/zero/1.0/ |
Abstract
Let $\mathcal{E}=\text{Rep}(G)$ be a Tannakian fusion category. For a braided fusion category $\mathcal{C}$ over $\mathcal{E}$ we give sufficient and necessary conditions that characterize the Witt relation $[\mathcal{C}]=[\mathcal{E}]$. Then we show the Witt group $\mathcal{W}(\mathcal{E})$ is naturally a direct sum of Witt group $\mathcal{W}:=\mathcal{W}(\text{Vec})$ and the group $\text{H}^4(G,\mathbb{K}^\times)$. Consequently, for any non-degenerate fusion category $\mathcal{C}$ over $\mathcal{E}$, there is a positive integer $n$ (e.g. $n=|G|$) such that $\mathcal{C}^{\boxtimes_\mathcal{E}^n}$ admits a minimal extension.
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"abstract": "Let $\\mathcal{E}=\\text{Rep}(G)$ be a Tannakian fusion category. For a braided fusion category $\\mathcal{C}$ over $\\mathcal{E}$ we give sufficient and necessary conditions that characterize the Witt relation $[\\mathcal{C}]=[\\mathcal{E}]$. Then we show the Witt group $\\mathcal{W}(\\mathcal{E})$ is naturally a direct sum of Witt group $\\mathcal{W}:=\\mathcal{W}(\\text{Vec})$ and the group $\\text{H}^4(G,\\mathbb{K}^\\times)$. Consequently, for any non-degenerate fusion category $\\mathcal{C}$ over $\\mathcal{E}$, there is a positive integer $n$ (e.g. $n=|G|$) such that $\\mathcal{C}^{\\boxtimes_\\mathcal{E}^n}$ admits a minimal extension.",
"arxiv_id": "2601.09060",
"authors": [
"Theo Johnson-Freyd",
"Victor Ostrik",
"Zhiqiang Yu"
],
"categories": [
"math.CT",
"math.KT",
"math.QA"
],
"license": "http://creativecommons.org/publicdomain/zero/1.0/",
"title": "On the structure of Witt groups and minimal extension conjecture",
"url": "https://arxiv.org/abs/2601.09060",
"version": "v1"
},
"schema_id": "dorsal/arxiv",
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