论文标题
评论“液体，固体和眼镜中的变形，放松和损坏的对称性：统一的拓扑场理论”
Comment on "Deformations, relaxation and broken symmetries in liquids, solids and glasses: a unified topological field theory"
论文作者
论文摘要
我们讨论了最近出版的液体，固体和眼镜的现场理论方法[Phys.Rev.e {\ bf105}，034108（2022）]，旨在在常见的量子形式主义中描述这些材料。我们认为，这种量子形式主义不适用于经典液体，并且所呈现的结果很大程度上依赖于从量子流体借来的相松弛的概念，这与已知的经典液体的流体动力学理论相矛盾。特别是，作者错过了重要的粒子守恒定律，而密度波动是流体动力慢的变量。取而代之的是，作者将金石玻色子作为基本流体动力激发。我们指出，在经典液体中，没有损坏的连续对称性，因此没有金石玻色子。作者声称，金石玻色子将负责液体中的声音存在，而不是由粒子数和动量保护的组合产生，这是流体力学教科书中有充分记录的事实。
We discuss a field-theoretical approach to liquids, solids and glasses, published recently [Phys.Rev.E {\bf105}, 034108 (2022)], which aims to describe these materials in a common quantum formalism. We argue that such quantum formalism is not applicable to classical liquids, and the results presented, which rely heavily on the concept of phase relaxation borrowed from quantum fluids, contradict the known hydrodynamic theory of classical liquids. In particular, the authors miss the important particle-number conservation law and the density fluctuations as hydrodynamic slow variable. Instead, the authors invoke Goldstone bosons as elementary hydrodynamic excitations. We point out that in a classical liquid there are no broken continuous symmetries and consequently no Goldstone bosons. The authors claim that the Goldstone bosons would be responsible for the existence of sound in liquids, instead of resulting from combined particle-number and momentum conservation, a fact well documented in fluid-mechanics textbooks.
