标题： 探测时空的时间方向性 显示英文标题

标题： Probing time orientability of spacetime

摘要： 在广义相对论、宇宙学和量子场论中，时空被假定为一个可定向的流形，并带有使其具有空间和时间可定向性的洛伦兹度规。 物理定律是否需要这些可定向性假设的问题最终是观察或实验性质的，或者答案可能来自物理学的基本理论。 时空时间不可定向的可能性尚未得到研究，因此不应立即被排除。 在本文中，我们主张可以通过涉及量子真空中电磁涨落的物理效应，局部探测闵可夫斯基空时空的潜在时间不可定向性。 我们旨在研究时间不可定向性对在配备时间不可定向拓扑的闵可夫斯基时空中受到这些电磁涨落影响的带电粒子随机运动的影响，以及其时间可定向的对应情况。 为此，我们引入并推导出统计时间可定向性指标的解析表达式。 然后我们表明，可以通过相应的可定向性指标显示的反转模式来确定时间不可定向的拓扑结构，而当底层流形是时间可定向时，这种模式是不存在的。 显示英文摘要

摘要： In general relativity, cosmology and quantum field theory, spacetime is assumed to be an orientable manifold endowed with a Lorentz metric that makes it spatially and temporally orientable. The question as to whether the laws of physics require these orientability assumptions is ultimately of observational or experimental nature, or the answer might come from a fundamental theory of physics. The possibility that spacetime is time non-orientable lacks investigation, and so should not be dismissed straightaway. In this paper, we argue that it is possible to locally access a putative time non-orientability of Minkowski empty spacetime by physical effects involving quantum vacuum electromagnetic fluctuations. We set ourselves to study the influence of time non-orientability on the stochastic motions of a charged particle subject to these electromagnetic fluctuations in Minkowski spacetime equipped with a time non-orientable topology and with its time orientable counterpart. To this end, we introduce and derive analytic expressions for a statistical time orientability indicator. Then we show that it is possible to pinpoint the time non-orientable topology through an inversion pattern displayed by the corresponding orientability indicator, which is absent when the underlying manifold is time orientable.