论文标题
$λ$的Penrose连接条件：对脉冲引力波的低调指标的几何见解
Penrose junction conditions with $Λ$: Geometric insights into low-regularity metrics for impulsive gravitational waves
论文作者
论文摘要
罗杰·彭罗斯（Roger Penrose）在1960年代末引入了敏科夫斯基空间中的冲动引力波，并在数十年中对其进行了广泛的研究。在这里，我们关注的是无X型波，后来已被普遍为冲动在所有恒定的背景中传播的冲动，即（反）De Sitter Universe。虽然彭罗斯的原始结构是基于他在平坦的背景下生动生动的几何“剪刀和纸上”方法，但直到最近，在宇宙学常数$λ\ not = 0 $的情况下一直缺少相似强大的可视化和理解。在这里，我们回顾了原始的Penrose构造及其对非逐步划分的$λ$的概括，以及最近建立的可视化：全球无效的Geodesics的一个特殊家族定义了适当的合并坐标系，允许将分布与持续的度量相关联。
Impulsive gravitational waves in Minkowski space were introduced by Roger Penrose at the end of the 1960s, and have been widely studied over the decades. Here we focus on nonexpanding waves which later have been generalized to impulses traveling in all constant-curvature backgrounds, i.e., the (anti-)de Sitter universe. While Penrose's original construction was based on his vivid geometric "scissors-and-paste" approach in a flat background, until recently a comparably powerful visualization and understanding has been missing in the case with a cosmological constant $Λ\not=0$. Here we review the original Penrose construction and its generalization to non-vanishing $Λ$ in a pedagogical way, as well as the recently established visualization: A special family of global null geodesics defines an appropriate comoving coordinate system that allows to relate the distributional to the continuous form of the metric.
