论文标题
VCDM中弹跳宇宙学
Bouncing Cosmology in VCDM
论文作者
论文摘要
我们在VCDM模型中构造了不对称的弹跳场景 - 也称为II型最小化重力，这是一种具有两个局部物理自由度的修饰的重力理论。该方案是免除任何幽灵或梯度不稳定性，临时匹配条件或各向异性应力问题（BKL不稳定性）。此外，它成功地产生了与观测值兼容的宇宙学扰动。标量光谱指数可以通过选择物质部门的方程以及VCDM电位的形式来调整标量指数，从而导致几乎规模不变的功率谱。满足张量与量表比的CMB边界会导致蓝色张量光谱。
We construct an asymmetric bouncing scenario within the VCDM model - also known as type-II minimally modified gravity -, a modified gravity theory with two local physical degrees of freedom. The scenario is exempt of any ghost or gradient instability, ad-hoc matching conditions or anisotropic stress issue (BKL instability). It moreover succeeds in generating the cosmological perturbations compatible with the observations. The scalar spectral index can be adapted by the choice of the equation of state of the matter sector and the form of the VCDM potential leading to an almost scale-invariant power spectrum. Satisfying the CMB bounds on the tensor-to-scalar ratio leads to a blue tensor spectrum.
