论文标题
曲率的指数功能修饰的重力
Modified gravity with an exponential function of curvature
论文作者
论文摘要
分析标量曲率指数函数在修饰的重力中的作用。提出了两个模型。一个符合本地和宇宙学限制的玩具模型，并对宇宙进化提供了适当的定性描述。该模型包含一个鞍物质临界点，可以发展为迟到的保姆吸引子。已经提出了初始条件，表明该玩具模型具有可接受的物质时代，并提供了宇宙进化的近似定性行为。第二个可行的模型在早期的行为非常接近$λ$ CDM，并且可以满足本地和宇宙学的约束。它的行为为$ r-2λ$在$ r \ rightarrow \ infty $上，趋向于$ r \ rightarrow 0 $零，包含平坦的时空解决方案。该模型提供了可行的宇宙学轨迹，作为第一个模型，将物质主导的点与迟到的保姆吸引子联系起来。该模型中主要密度参数的宇宙演化与当前观察结果一致，其方程式非常接近$ -1 $。
The role of an exponential function of the scalar curvature in the modified gravity is analyzed. Two models are proposed. A toy model that complies with local and cosmological constraints and gives appropriate qualitative description of the cosmic evolution. This model contains a saddle matter-dominant critical point that can evolve towards a late time de Sitter attractor. Initial conditions have been proposed, showing that this toy model has an acceptable matter era and gives an approximate qualitative behavior of cosmic evolution. A second viable model, behaves very close to $Λ$CDM at early times and can satisfy local and cosmological constraints. It behaves as $R-2Λ$ at $R\rightarrow \infty$ and tends to zero at $R\rightarrow 0$, containing flat spacetime solution. The model gives viable cosmological trajectories that, as the first model, connect the matter dominated point with a late time de Sitter attractor. The cosmic evolution of the main density parameters in this model is consistent with current observations with an equation of state very close to $-1$.
