论文标题
量子极权性能和确切的对称性
The Quantum Totalitarian Property and Exact Symmetries
论文作者
论文摘要
我们讨论了一个观点，该观点是文献中不时怀疑的：所有对称性，例如由能量和动量保护定律引起的符号，不仅在量子物理学中保持“平均”，不仅是“平均”，而且在波浪函数的每个“分支”中，都以可观察的可观察到敏锐的方式表示。我们注意到，要从这种意义上（不仅是平均而言）为量子系统准确地持有，因此必须假设所谓的“量子理论的极权性能”，即必须对任何能够测量量子观察到的能够自身进行量化的系统进行量化。因此，如果保护定律要准确地持有，则“经典测量设备”（即不受分支结构的约束）的概念是站不住脚的。我们还指出，在经典物理学中具有明确定义的公式的任何其他原理（例如等效原理）也应以完全相同的方式（即通过分支分支）扩展到量子域。
We discuss a point, which from time to time has been doubted in the literature: all symmetries, such as those induced by the energy and momentum conservation laws, hold in quantum physics not just "on average", as is sometimes claimed, but exactly in each "branch" of the wavefunction, expressed in the basis where the conserved observable is sharp. We note that for conservation laws to hold exactly for quantum systems in this sense (not just on average), it is necessary to assume the so-called "totalitarian property of quantum theory", namely that any system capable of measuring a quantum observable must itself be quantised. Hence, if conservation laws are to hold exactly, the idea of a `classical measuring apparatus' (i.e., not subject to the branching structure) is untenable. We also point out that any other principle having a well-defined formulation within classical physics, such as the Equivalence principle, is also to be extended to the quantum domain in exactly the same way, i.e., branch by branch.
