We shed some light on the reason why the accidental flatness constraint appears in certain limits of the amplitudes of covariant loop quantum gravity. We show why this constraint is harmless, by displaying how analogous accidental constraints appear in transition amplitudes of simple systems, when certain limits are considered.

中文翻译：

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偶然的平坦度约束并不意味着错误的经典极限

我们阐明了为什么在协变环量子引力振幅的某些限制中出现偶然平坦度约束的原因。我们展示了为什么这种约束是无害的，通过展示在考虑某些限制时类似的偶然约束如何出现在简单系统的过渡幅度中。