Time-reparametrization invariance in eternal inflation
Time-reparametrization invariance in eternal inflation
复制标题
永恒暴胀中的时间重参数化不变性
DOI：
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发表时间：
2005
期刊：
影响因子：
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通讯作者：
S. Winitzki
中科院分区：
文献类型：
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作者：
S. Winitzki
我解决一些最近提出的问题，关于时间参数化的依赖，在随机描述永恒的通货膨胀。为了阐明时间规范的选择所起的作用，我展示了关于永恒膨胀时空中的物理观测量的规范依赖和规范独立陈述的例子。特别是，热化和膨胀区域的相对丰度是高度规范依赖的。膨胀区域的3-体积的无界增长在某些时间规范中被发现，例如真时规范或标度因子规范。然而，在相同的时空中，存在有限的和单调递减的3体积的时间叶理，我证明了一个明确的建设。我还表明，存在没有选择的时间规范，将产生一个公正的稳态概率分布的热化区域中的观测。
I address some recently raised issues regarding the time-parametrization dependence in stochastic descriptions of eternal inflation. To clarify the role of the choice of the time gauge, I show examples of gauge-dependent as well as gauge-independent statements about physical observables in eternally inflating spacetimes. In particular, the relative abundance of thermalized and inflating regions is highly gauge-dependent. The unbounded growth of the 3-volume of the inflating regions is found in certain time gauges, such as the proper-time or the scale-factor gauge. Yet in the same spacetimes there exist time foliations with a finite and monotonically decreasing 3-volume, which I demonstrate by an explicit construction. I also show that there exists no choice of the time gauge that would yield an unbiased stationary probability distribution for observables in thermalized regions.