Time-Symmetric Counterfactual Propositions in Quantum Theory

Ruth Kastner量子理论中的时间对称反事实命题量子理论中的许多解释问题涉及反事实陈述（形式为“如果是P，那么就是Q”的陈述）。近年来，在量子理论的明确时间对称公式中，反事实主张的有效性一直存在争议，例如Yakir Aharonov和Lev Vaidman以及Ulrich Mohrhoff。 拟议项目的目标是双重的：（a）精确地调查如何这样的反事实必须不同于传统的反事实和（B）是否一致的和/或物理上有意义的时间对称量子反事实的帐户是可能的。研究计划是对反事实的文献进行彻底的调查，以考虑现有的理论，并确定这些理论的领域（即，这些理论所处理的反事实主张的种类）。 然后分析传统反事实主张和当前提案所涉及的新型反事实主张（以下简称“新型反事实”）的显著特征，以揭示本质上的相似性和（主要）差异。 接下来，该项目转向主要的传统反事实理论的批判性分析，根据新的反事实索赔和传统的反事实索赔之间的差异。这样的分析应该至少为传统理论是否可以应用于新的反事实（可能需要进行一些修改）的问题提供部分答案。 如果确定传统的反事实理论与新的反事实理论根本不相容，那么接下来将尝试展示另一种反事实理论的基本特征（解决第一点），然后将对其进行批判性分析（解决第二点）。 如果第二点的结果是否定的，那么我们就探索使用反事实测量的替代方法，以建立像Mohrhoff所寻求的那样有意义的时间对称的“客观”量子力学概率。

Ruth KastnerTime-Symmetric Counterfactual Propositions in Quantum TheoryMany interpretational problems in quantum theory involve counterfactual statements (statements of the form, \If it were that P, then it would be that Q"). In recent years, there has been controversy over the validity of counterfactual claims in explicitly time symmetric formulations of quantum theory such as that ofYakir Aharonov and Lev Vaidman, and that of Ulrich Mohrhoff. The goal of the proposed project is twofold: (a) to investigate precisely how such counterfactuals must differ from conventional counterfactuals and (b) whether a consistent and/or physically meaningful account of time-symmetric quantum counterfactual is possible. The research plan is to conduct a thorough survey of the literature on counterfactuals, in order to take account of existing theories and to ascertain the domain of those theories (i.e., the kinds of counterfactual claims addressed by those theories). Then an analysis follows of the salient features of traditional counterfactual claims and of the novel counterfactual claims addressed by the current proposal (hereinafter \novel counterfactuals"), in order to uncover essential similarities and (primarily) differences. Next the project turns to a critical analysis of the predominant traditional counterfactual theories in light of differences uncovered between novel counterfactual claims and the traditional counterfactual claims. Such an analysis should provide at least a partial answer to the question of whether traditional theories can be applied to novel counterfactuals, possibly with some modifications. If it is determined that traditional counterfactual theories are fundamentally incompatible with novel counterfactuals, then an attempt follows to lay out the essential features of an alternative counterfactual theory (addressing the first point), which will then be critically analyzed (addressing the second point) . If the result of this second point is negative, alternatives to the use of counterfactual measurements are explored, to establish meaningful time-symmetric \objective" quantum mechanical probabilities such as that sought by Mohrhoff.