论文标题
超越半古老时间
Beyond semiclassical time
论文作者
论文摘要
我们表明，在量子重力中使用的通常的近似类型近似类型，其中半经典时间参数来自Wheeler-Dewitt约束的弱耦合膨胀，至少导致一个单位理论，至少在迷你Uperspace模型中以近代领导的顺序。由于没有单位性侵入性术语，这解决了该命令中的单位性问题，这在文献中一直在争论。此外，我们还表明，从某种意义上说，该度量与与选择半经典时间作为重新培训量表相关的faddeev-popov决定因素，因此对保守的内部产物进行了固定。这意味着，对时间问题的出生探测方法实际上是一个关系量子理论的实例，其中过渡幅度可以与条件概率有关。
We show that the usual Born-Oppenheimer type of approximation used in quantum gravity, in which a semiclassical time parameter emerges from a weak-coupling expansion of the Wheeler-DeWitt constraint, leads to a unitary theory at least up to the next-to-leading order in minisuperspace models. As there are no unitarity-violating terms, this settles the issue of unitarity at this order, which has been much debated in the literature. Furthermore, we also show that the conserved inner product is gauge-fixed in the sense that the measure is related to the Faddeev-Popov determinant associated with the choice of semiclassical time as a reparametrization gauge. This implies that the Born-Oppenheimer approach to the problem of time is, in fact, an instance of a relational quantum theory, in which transition amplitudes can be related to conditional probabilities.
