论文标题
通过结合弦乐宇宙学和电力法通货膨胀来创建空间平坦度
Creating Spatial Flatness by Combining String Gas Cosmology and Power Law Inflation
论文作者
论文摘要
我们表明，有可能结合弦气宇宙学的早期阶段，该阶段可以解释宇宙学量表上观察到的结构的起源，并在短期的较短时期膨胀，从而产生空间平坦。最终的模型与``Swampland Criteria''一致，并且来自{\ it Trans-Planckian审查构想}的约束。仅使用规范的慢速通货膨胀，这种结构是不可能的，但是它可以在温暖的通货膨胀情况下或具有指数潜力的冷通货膨胀中出现。由此产生的宇宙学是非单一的。我们讨论导致场景的宇宙学扰动范围。在大尺度上（初始弦气相后的比例比哈勃半径大），频谱由在原始阶段设置的热串气体波动确定，并且几乎是尺度不变的，略有红色倾斜。在小尺度上，通货膨胀期间产生的扰动占主导地位。在这些尺度上，频谱再次几乎是尺度不变的。有一个中间范围（在通货膨胀期间进入哈勃半径的尺度），在该范围内，弦气波动受到抑制，但在通货膨胀期间产生的量表继续占主导地位。在这些尺度上，光谱具有$ n_s -1 \ sim -2 $的尖锐红色频谱索引。
We show that it is possible to combine an early phase of String Gas Cosmology which can explain the origin of the observed structures on cosmological scales with a short later period of power law inflation which creates spatial flatness. The resulting model is consistent with the ``swampland criteria'' and the constraints coming from the {\it Trans-Planckian Censorship Conjecture}. Such a construction is not possible using only canonical slow-roll inflation, but it can emerge in the warm inflation scenario or in cold inflation with an exponential potential. The resulting cosmology is non-singular. We discuss the spectrum of cosmological perturbations resulting in our scenario. On large scales (scales which remain larger than the Hubble radius after the initial string gas phase) the spectrum is determined by the thermal string gas fluctuations set up in the primordial phase, and it is almost scale-invariant with a slight red tilt. On small scales, the perturbations produced during the inflationary phase dominate. On these scales, the spectrum is once again nearly scale-invariant. There is an intermediate range (scales which enter the Hubble radius during the period of inflation) where the string gas fluctuations are damped but continue to dominate over those produced during the period of inflation. On these scales the spectrum has a sharp red spectral index of $n_s - 1 \sim -2$.
