The operational formulations of quantum theory are drastically time oriented. However, to the best of our knowledge, microscopic physics is time-symmetric. We address this tension by showing that the asymmetry of the operational formulations does not reflect a fundamental time-orientation of physics. Instead, it stems from built-in assumptions about the $users$ of the theory. In particular, these formalisms are designed for predicting the future based on information about the past, and the main mathematical objects contain implicit assumption about the past, but not about the future. The main asymmetry in quantum theory is the difference between knowns and unknowns.

中文翻译：

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量子理论操作公式中的时间箭头

量子理论的操作公式是完全面向时间的。然而，据我们所知，微观物理学是时间对称的。我们通过表明操作公式的不对称性并不反映物理学的基本时间取向来解决这种紧张关系。相反，它源于关于该理论的 $users$ 的内置假设。特别是，这些形式主义是为了根据过去的信息预测未来而设计的，主要的数学对象包含关于过去的隐含假设，而不是关于未来的假设。量子理论中的主要不对称性是已知和未知之间的差异。