标题： 有效暗能量模型和在$F(T)$引力框架下的有弹跳的暗能量模型 显示英文标题

标题： Effective Dark Energy Models and Dark Energy Models with Bounce in frames of $F(T)$ Gravity

摘要： 各种在$F(T)$引力框架下的宇宙学模型被考虑。 提出了构建具有不同演化的有效暗能量模型的一般方案。 表明这些模型在原则上与$\Lambda$CDM 模型相容。 由$F(T)$引力支配的宇宙动力学在过去可以模仿$\Lambda$CDM 演化，但在未来会偏离它。 我们还构建了一些具有“真实”（非有效）状态方程参数$w$的暗能量模型，使得$w\leq-1$。 表明在$F(T)$引力中，充满幻影场的宇宙不一定以奇点结束其存在。 有两种可能的机制允许最终奇点的存在。 首先由于能量密度与$H^{2}$之间的非线性依赖关系（$H$是哈勃参数），宇宙的膨胀不像在广义相对论中那样快，实际上会发生小撕裂阶段而不是大撕裂。 我们还考虑了未来可能有反弹的模型。 在这些模型中，宇宙的膨胀可以模仿未来奇点的动力学，但由于未来的反弹，宇宙开始收缩。 显示英文摘要

摘要： Various cosmological models in frames of $F(T)$ gravity are considered. The general scheme of constructing effective dark energy models with various evolution is presented. It is showed that these models in principle are compatible with $\Lambda$CDM model. The dynamics of universe governed by $F(T)$ gravity can mimics $\Lambda$CDM evolution in past but declines from it in a future. We also construct some dark energy models with the "real" (non-effective) equation-of-state parameter $w$ such that $w\leq-1$. It is showed that in $F(T)$ gravity the Universe filled phantom field not necessarily ends its existence in singularity. There are two possible mechanisms permitting the final singularity. Firstly due to the nonlinear dependence between energy density and $H^{2}$ ($H$ is the Hubble parameter) the universe can expands not so fast as in the general relativity and in fact Little Rip regime take place instead Big Rip. We also considered the models with possible bounce in future. In these models the universe expansion can mimics the dynamics with future singularity but due to bounce in future universe begin contracts.