Bouhmadi-López Mariam, Errahmani Ahmed, Ouali Taoufik, Tavakoli Yaser
1Department of Theoretical Physics University of the Basque Country UPV/EHU, P.O. Box 644, 48080 Bilbao, Spain.
2IKERBASQUE, Basque Foundation for Science, 48011 Bilbao, Spain.
Eur Phys J C Part Fields. 2018;78(4):330. doi: 10.1140/epjc/s10052-018-5773-5. Epub 2018 Apr 23.
The background cosmological dynamics of the late Universe is analysed on the framework of a dark energy model described by an holographic Ricci dark energy component. Several kind of interactions between the dark energy and the dark matter components are considered herein. We solve the background cosmological dynamics for the different choices of interactions with the aim to analyse not only the current evolution of the universe but also its asymptotic behaviour and, in particular, possible future singularities removal. We show that in most of the cases, the Big Rip singularity, a finger print of this model in absence of an interaction between the dark sectors, is substituted by a de Sitter or a Minkowski state. Most importantly, we found two new bouncing solutions leading to two possible asymptotic behaviours, we named Little Bang and Little Sibling of the Big Bang. At a Little Bang, as the size of the universe shrinks to zero in an infinite cosmic time, the Hubble rate and its cosmic time derivative blow up. In addition, at a Little sibling of the Big Bang, as the size of the universe shrinks to zero in an infinite cosmic time, the Hubble rate blows up but its cosmic time derivative is finite. These two abrupt events can happen as well in the past.
在由全息里奇暗能量分量描述的暗能量模型框架下，分析了晚期宇宙的背景宇宙动力学。本文考虑了暗能量与暗物质分量之间的几种相互作用。我们针对不同的相互作用选择求解背景宇宙动力学，目的不仅是分析宇宙当前的演化，还包括其渐近行为，特别是可能消除未来奇点的情况。我们表明，在大多数情况下，大撕裂奇点（在暗区之间没有相互作用时该模型的一个特征）被德西特或闵可夫斯基状态所取代。最重要的是，我们发现了两种新的反弹解，导致两种可能的渐近行为，我们将其命名为小爆炸和大爆炸的小同胞。在小爆炸时，随着宇宙大小在无限宇宙时间内收缩至零，哈勃率及其宇宙时间导数会发散。此外，在大爆炸的小同胞处，随着宇宙大小在无限宇宙时间内收缩至零，哈勃率会发散但其宇宙时间导数是有限的。这两个突变事件在过去也可能发生。
