首页> 外文期刊>Physical review, D >Regge calculus models of the closed vacuum Lambda-FLRW universe
【24h】

Regge calculus models of the closed vacuum Lambda-FLRW universe

机译:封闭式真空λ-FLRW宇宙的调节模型模型

获取原文
获取原文并翻译 | 示例
           

摘要

The Collins-Williams Regge calculus models of Friedmann-Lemaitre-Robertson-Walker (FLRW) space-times and Brewin's subdivided models are applied to closed vacuum Lambda-FLRW universes. In each case, we embed the Regge Cauchy surfaces into 3-spheres in E-4 and consider possible measures of Cauchy surface radius that can be derived from the embedding. Regge equations are obtained from both global variation, where entire sets of identical edges get varied simultaneously, and local variation, where each edge gets varied individually. We explore the relationship between the two sets of solutions, the conditions under which the Regge Hamiltonian constraint would be a first integral of the evolution equation, the initial value equation for each model at its moment of time symmetry, and the performance of the various models. It is revealed that local variation does not generally lead to a viable Regge model. It is also demonstrated that the various models do satisfy their respective initial value equations. Finally, it is shown that the models reproduce the correct qualitative dynamics of the space-time. Furthermore, the approximation's accuracy is highest when the universe is small but improves overall as we increase the number of tetrahedra used to construct the Regge Cauchy surface. Eventually though, all models gradually fail to keep up with the continuum FLRW model's expansion, with the models with lower numbers of tetrahedra falling away more quickly. We believe this failure to keep up is due to the finite resolution of the Regge Cauchy surfaces trying to approximate an ever expanding continuum Cauchy surface; each Regge surface has a fixed number of tetrahedra and as the surface being approximated gets larger, the resolution would degrade. Finally, we note that all Regge models end abruptly at a point when the timelike struts of the skeleton become null, though this end point appears to get delayed as the number of tetrahedra is increased.
机译:Friedmann-Lemaitre-Robertson-Walker(FLRW)空间时间和Brewin的细分模型的柯林斯-Williams Regge模型适用于封闭的真空Lambda-Flrw宇宙。在每种情况下,我们将Regge Cauchy表面嵌入E-4中的3个球体中,并考虑可以源自嵌入的Cauchy表面半径的可能测量。从全局变型获得调节方程,其中整组相同的边缘同时变化,以及每个边缘的局部变化单独变化。我们探讨了两组解决方案之间的关系,调节汉密尔顿约束是进化方程的第一积分的条件,其时刻对称时刻的每个模型的初始值方程,以及各种型号的性能。据透露,局部变异通常不会导致可行的调节模型。还证明各种模型确实满足了它们各自的初始值方程。最后,表明模型再现了时空的正确定性动态。此外,当宇宙较小时,近似的准确性最高,但随着我们增加用于构建Regge Cauchy表面的四面体的数量,总体而言。最终,所有型号都无法跟上连续的FLRW模型的扩展,其中型号较少的四面体数量迅速地掉落。我们相信这种未能跟上的是由于调节陶池表面的有限分辨率,试图近似扩大连续的连续欧洲表面;每个Regge表面具有固定数量的四面体,随着近似的表面变大,分辨率会降低。最后,我们注意到所有调节模型在骨架的时间表支柱变为空中时突然结束,尽管随着Tetrahedra的数量增加,但该终点似乎延迟延迟。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱:kefu@zhangqiaokeyan.com

京公网安备:11010802029741号 ICP备案号:京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有
  • 客服微信

  • 服务号