标题： 爱因斯坦的电子与局部分支：幺正性不需要多世界 显示英文标题

标题： Einstein's Electron and Local Branching: Unitarity Does not Require Many-Worlds

摘要： 我们重新审视爱因斯坦1927年的电子衍射思想实验，使用单电子源和不透明半球形探测器阵列，这在现代传感器中现在可以实现。 在这个完全封闭的系统中，没有信号从半球逃逸，我们提供了对多世界诠释（MWI）和分支希尔伯特子空间诠释（BHSI）的直接实证比较。 两者都保持幺正性而无需引入波函数坍缩，如哥本哈根诠释（CI）所做的那样，但它们在本体论上有所不同：MWI提出不可逆的全球分支进入平行世界，而BHSI描述局部的、可能可逆的分支进入退相干子空间。 在此设置中，所有量子事件（分支、参与、脱离和重新定位）都完全发生在局部系统内，玻恩规则通过分支权重自然出现，可以在探测器统计中观察到。 为了更全面地探索分支动力学，我们建议采用增强的双层实验设置，其中包含一个内部透明探测器。 由于电子在两层之间的传输时间短于内部传感器的平均响应时间，这允许对测量时间以及潜在异常（如延迟或未决定的选择）进行关键测试。 我们的分析挑战了幺正性需要平行世界的观点，而是倡导一种更简单的观点：局部的、幺正的分支，无需坍缩或全局分裂。 显示英文摘要

摘要： We revisit the 1927 thought experiment of Einstein on electron diffraction, using a single-electron source and an opaque hemispheric detector array, now achievable with modern sensors. In this fully enclosed system, where no signals escape the hemisphere, we provide a direct empirical comparison of the Many-Worlds Interpretation (MWI) and the Branched Hilbert Subspace Interpretation (BHSI). Both maintain unitarity without invoking wavefunction collapse, as in the Copenhagen Interpretation (CI), but differ ontologically: MWI proposes irreversible global branching into parallel worlds, while BHSI describes local, potentially reversible branching into decohered subspaces. In this setup, all quantum events (branching, engagement, disengagement, and relocation) occur entirely within the local system, and the Born rule, naturally emerging through branch weights, can be observed in detector statistics. To explore branching dynamics more thoroughly, we suggest an enhanced dual-layer experimental setup with an inner transparent detector. Because the electron transit time between layers is shorter than the average response times of the inner sensors, this allows for a crucial test of measurement timing and potential anomalies, such as delayed or uncommitted choices. Our analysis challenges the notion that unitarity necessitates parallel worlds, instead advocating for a simpler view: local, unitary branching without collapse or global splitting.