A crucial aspect of anti-de Sitter space is that it has a boundary where time is well defined.
A crucial aspect of anti-de Sitter space is that it has a boundary where time is well defined.
反德西特时空的一个特殊性质是它有个边界，边界上还有明确的时间轴。
A crucial aspect of anti-de Sitter space is that it has a boundary where time is well defined.
反德西特时空的一个特殊性质是它有个边界，边界上还有明确的时间轴。