论文标题
Cuscuton Bounce的光谱
Spectrum of Cuscuton Bounce
论文作者
论文摘要
最近已经显示，基于Cuscuton重力的宇宙弹跳模型没有任何幽灵或曲率不稳定性。我们探索Cuscuton Bounce是否可以为产生近规模不变标量扰动提供通货膨胀的替代方案。虽然单场cuscuton弹跳通常会产生强蓝色的功率谱（对于各种初始/边界条件），但我们证明可以在始于绝热真空的观众场中生成比例不变的熵模式，并且在运动型上是在动力学上均可生成的。此外，我们的解决方案没有奇异性，也不需要临时匹配条件。我们还研究了Cuscuton Bounce中张量模式（或重力波）的产生，并表明它们稳定，类似于其他弹跳模型，但生产的频谱是强烈的蓝色且无法观察的。
It has been recently shown that a cosmological bounce model based on Cuscuton gravity does not have any ghosts or curvature instabilities. We explore whether Cuscuton bounce can provide an alternative to inflation for generating near scale-invariant scalar perturbations. While a single field Cuscuton bounce generically produces a strongly blue power spectrum (for a variety of initial/boundary conditions), we demonstrate that scale invariant entropy modes can be generated in a spectator field that starts in adiabatic vacuum, and is kinetically coupled to the primary field. Furthermore, our solution has no singularity, nor requires an ad hoc matching condition. We also study the generation of tensor modes (or gravitational waves) in Cuscuton bounce and show that while they are stable, similar to other bounce models, the produced spectrum is strongly blue and unobservable.
