论文标题
宇宙学时间功能和灯光般的光线
The cosmological time functions and lightlike rays
论文作者
论文摘要
事实证明，有限的宇宙学时间功能$τ$的所有不连续点都在过去的灯光射线上。结果，证明，如果$（m，g）$是没有过去灯光射线的时间表时空，那么$ g $的代表使其宇宙学时间功能是常规的。此外，通过降低规律性条件，给出了足够的因果简单性和时空假性因果关系的条件。还可以证明，如果$（m，g）$是时空，与Minkowski时空的开放子空间或$τ$连续相连，则可以降低规律性的第二条件，仅在不可延伸的过去因果射线上满足。
It is proved that all discontinuity points of a finite cosmological time function, $τ$, are on past lightlike rays. As a result, it is proved that if $(M,g)$ is a chronological space-time without past lightlike rays then there is a representation of $g$ such that its cosmological time function is regular. In addition, by reducing conditions of regularity sufficient conditions for causal simplicity and causal pseudoconvexity of space-time is given. It is also proved that the second condition of regularity can be reduced to satisfies only on inextendible past-directed causal rays if $(M,g)$ be a space-time, conformal with an open subspace of Minkowski space-time or $τ$ be continuous.
