论文标题
越过大爆炸奇点
Crossing the Big Bang singularity
论文作者
论文摘要
标量场和重力的简单模型允许跨越大爆炸奇点的同质各向同性宇宙解决方案。在具有依赖有效planck质量的场的缩放框架中，这些解决方案是规则的。它们在爱因斯坦框架中变得奇异。由于指标向爱因斯坦框架的场转换在消失的标量场的交叉点上是奇异的，因此出现了这种场奇异性。这些解决方案没有物理上的奇异性。在不超过两个衍生物的一般模型中，我们发现“大爆炸奇点”穿越的可能性不是通用的。它需要调整模型参数。目前的模型不是对宇宙的现实描述，因为它们无法使可接受的不均匀性。
A simple model for a scalar field and gravity admits homogeneous isotropic cosmological solutions which cross the Big Bang singularity. In the scaling frame with field dependent effective Planck mass these solutions are regular. They become singular in the Einstein frame with fixed Planck mass. This field singularity arises since the field transformation of the metric to the Einstein frame is singular at the crossing point of a vanishing scalar field. No physical singularity is present for these solutions. Within general models with no more than two derivatives we find that the possibility of a crossing of the "Big Bang singularity" is not generic. It needs a tuning of model parameters. The present models are not a realistic description of the Universe since they fail to render acceptable inhomogeneities.
