We show that crossing symmetry of S matrices is modified in certain theories with noninvertible symmetries or anomalies. Focusing on integrable flows to gapped phases in two dimensions, we find that S matrices derived previously from the bootstrap approach are incompatible with noninvertible symmetries along the flow. We present consistent alternatives, which, however, violate standard crossing symmetry and obey modified rules dictated by fusion categories. We extend these rules to theories with discrete anomalies. Published by the American Physical Society 2024

中文翻译：

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不可逆对称性、异常和散射振幅


我们表明，在某些具有不可逆对称性或异常的理论中，S 矩阵的交叉对称性被修改。专注于二维到间隙相的可积流动，我们发现先前从 bootstrap 方法推导出的 S 矩阵与沿流的不可逆对称性不兼容。我们提出了一致的替代方案，但是，这些替代方案违反了标准交叉对称性并遵循由融合类别决定的修改规则。我们将这些规则扩展到具有离散异常的理论。 美国物理学会 2024 年出版