论文标题
关于通用重力理论中明显的超亮驱动器
About apparent superluminal drives in generic gravity theories
论文作者
论文摘要
众所周知，在GR中存在扭曲驱动器，例如Alcubierre Bubbles，其明显的速度比Light Travel \ Cite {Alcubierre}快。由于Gao和Wald \ cite {gaowald}引起的结果表明，对于GR而言，这种旅行不太可能，因为它满足了无效能量和无效的通用条件。由于加洛韦（Galloway）引起的该陈述的概括，它可以确保Gao-wald结果是正确的，无论其潜在的重力模型如何，除非存在至少一个不可延迟的无效的无效测量，却在时空（无效线）中存在achronal图像。该主张的证明是基于因果理论的技术，并且从未被释放。在目前的工作中，通过使用Raychaudhuri方程式提供了对该结果的独立证明，并避免了文本中描述的几种技术并发症。最后一节讨论了这些肯定的某些后果，特别是它们在因果关系问题中的潜在用途。
As is well known, there exists warp drives in GR, such as the Alcubierre bubbles, which achieve an apparent faster than light travel \cite{alcubierre}. A result due to Gao and Wald \cite{gaowald} suggests that such a travel is unlikely for GR with matter satisfying both the Null Energy and the Null Generic Conditions. There exists a generalization of this statement due to Galloway, that ensures that the Gao-Wald result is true regardless the underlying gravity model, unless there exists at least one inextendible null geodesic with achronal image in the space time (a null line). The proof of this proposition is based on techniques of causal theories, and has never been released. In the present work an independent proof of this result is presented by use of the Raychaudhuri equation, and avoiding several technical complications described along the text. Some consequences of these affirmations are discussed at last section, in particular their potential use in problems of causality.
