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arXiv 1807.07587gr-qcastro-ph.COhep-ph
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宇宙学中的视(引力)视界

The Apparent (Gravitational) Horizon in Cosmology

Fulvio Melia

摘要:

在广义相对论中,引力视界(通常称为“视视界”)是一个假想的表面,所有零测地线都从观察者那里后退。宇宙有一个明显的(引力)视界,但与史瓦西和克尔度量中的对应物不同,它不是静态的。它可能最终变成一个事件视界--一个渐近定义的膜,永远将因果联系的事件与那些没有因果联系的事件分开--这取决于宇宙流体的状态方程。在本文中,我们研究了如何以及为什么在弗里德曼-罗伯逊-沃克度规中表现出明显的(引力)视界,以及为什么它对我们正确解释宇宙学数据变得如此关键。我们讨论了它的观测特征,并展示了它如何单独定义我们可见宇宙的适当大小。在这样做的时候,我们肯定了它的物理现实及其对宇宙学模型的影响。

英文摘要:

In general relativity, a gravitational horizon (more commonly known as the "apparent horizon") is an imaginary surface beyond which all null geodesics recede from the observer. The Universe has an apparent (gravitational) horizon, but unlike its counterpart in the Schwarzschild and Kerr metrics, it is not static. It may eventually turn into an event horizon---an asymptotically defined membrane that forever separates causally connected events from those that are not---depending on the equation of state of the cosmic fluid. In this paper, we examine how and why an apparent (gravitational) horizon is manifested in the Friedmann-Robertson-Walker metric, and why it is becoming so pivotal to our correct interpretation of the cosmological data. We discuss its observational signature and demonstrate how it alone defines the proper size of our visible Universe. In so doing, we affirm its physical reality and its impact on cosmological models.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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