论文标题
相对论刚性系统和宇宙扩展
Relativistic rigid systems and the cosmic expansion
论文作者
论文摘要
我们分析了身体在不断扩展的宇宙学宇宙中保持僵化的必要条件。首先，我们建立了在一般时空以及新的准刚性概念中具有刚体的主要定理和定义。我们将获得的结果应用于均匀的宇宙，该宇宙探索了平稳时段的差异。我们讨论刚体的概念如何有助于理解宇宙学中空间的扩展。最后，使用刚性系统作为参考框架，我们计算重力能，并将其与文献中的先前结果进行比较。
We analyze the necessary conditions for a body to remain rigid in an expanding cosmological Universe. First, we establish the main theorems and definitions for having a rigid body in a general spacetime as well as the new concept of quasilocal rigidity. We apply the obtained results to a homogeneous universe exploring the differences with flat spacetime. We discuss how the concept of rigid body helps to understand the expansion of space in cosmology. Finally, using a rigid system as a reference frame, we calculate the gravitational energy, and we compare it with previous results in the literature.
