论文标题
在非明智的Horndeski宇宙学中产生宇宙学的扰动
Generating cosmological perturbations in non-singular Horndeski cosmologies
论文作者
论文摘要
过去，我们构建了一个霍德斯基反弹的混凝土模型，过去具有很强的重力。在该模型中，我们表明，宇宙学扰动的正确光谱可以在早期收缩时期产生，并进行轻度的微调确保标量频谱倾斜$ n_s $和张量与标准比率$ $ $ $ $ $与观察结果一致。 $ r $的较小度受标量音速的较小度约束。由于过去的强大耦合，在我们的设置中禁止任意$ r $的小值。然而，我们表明可以以可控制的方式产生扰动，即在经典田地理论中合法描述背景进化和扰动的制度，并且弱耦合的量子理论。
We construct a concrete model of Horndeski bounce with strong gravity in the past. Within this model we show that the correct spectra of cosmological perturbations may be generated at early contracting epoch, with mild fine-tuning ensuring that the scalar spectral tilt $n_S$ and tensor-to-scalar ratio $r$ are consistent with observations. The smallness of $r$ is governed by the smallness of the scalar sound speed. Arbitrarily small values of $r$ are forbidden in our setup because of the strong coupling in the past. Nevertheless, we show that it is possible to generate perturbations in a controllable way, i.e. in the regime where the background evolution and perturbations are legitimately described within classical field theory and weakly coupled quantum theory.
