论文标题
中间QCD轴
The meso-inflationary QCD axion
论文作者
论文摘要
我们研究了通货膨胀开始后自发损坏的轴突Peccei-quinn对称性的可能性。这种情况在通货膨胀前和通货膨胀后的轴心宇宙学之间进行了插值，两者都具有显着的现象学差异。由于在通货膨胀的早期阶段不存在轴，仅在不受CMB约束的尺度上产生大型通货膨胀波动，从而避免了最强的同化限制。然而，在短尺度上的等化扰动中的能量密度可以与未对准的绝热贡献相提并论。这些大的过度繁殖会导致轴突迷你群体的形成，并从Lyman-$α$森林和未来的CMB光谱失真测量中受到约束。如果在第一个O（25）通货膨胀的E（25）e折中损坏了Peccei-Quinn对称性，则不会从字符串网络中产生轴，但是灭绝域壁的贡献可以进一步增强丰度。如果通货膨胀期间的哈勃尺度下降到Peccei-Quinn对称性量表以下，但可以实现其他实现，则这种情况是最小化的。
We study the possibility that the axion Peccei-Quinn symmetry is spontaneously broken after the beginning of inflation. This scenario interpolates between pre-inflationary and post-inflationary axion cosmology with significant phenomenological differences from both. Since the axion is not present at the early stages of inflation large inflationary fluctuations are produced only at scales not constrained by CMB, avoiding the strongest isocurvature constraints. The energy density in isocurvature perturbations at short scales however can be comparable with the adiabatic contribution from misalignment. These large overdensities can lead to the formation of axion mini-clusters and also to constraints from Lyman-$α$ forest and future CMB spectral distortion measurements. If Peccei-Quinn symmetry is broken during the first O(25) e-foldings of inflation no axions are produced from the string network but contributions from the annihilation of domain walls can further boost the abundance. This scenario is minimally realized if the Hubble scale during inflation drops below the Peccei-Quinn symmetry breaking scale but other realizations are possible.
