发表机构
Leibniz University Hannover; Max Planck Institute for Gravitational Physics, Albert Einstein Institute（汉诺威莱布尼茨大学; 马克斯·普朗克引力物理研究所，爱因斯坦研究所）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本研究证明有限时间宇称破缺源产生的引力波背景低频尾部普遍无偏振，手征性分数随频率线性下降，并归因于大尺度上两种螺旋度产生效率几乎相同。
AI 中文摘要
早期宇宙中的宇称破缺可能导致手征引力波背景的产生。我们证明，对于有限时间的宇称破缺源，所产生的手征引力波背景的低频尾部普遍是无偏振的，且手征性分数随频率线性下降。我们的结果普遍适用于任何在波动方程中以二次形式出现的宇称破缺引力波源。我们同时考虑了高斯源和显式的三谱模板。我们将低频尾部缺乏手征性归因于以下事实：在大尺度上，引力波产生对两种螺旋度几乎同样低效。
英文摘要
Parity violation in the early Universe may lead to a chiral gravitational wave background. We show that, for finite-time parity-violating sources, the low-frequency tail of the generated chiral gravitational wave background is universally unpolarized, and that the chirality fraction decreases linearly with frequency. Our result generally applies to any parity-violating gravitational-wave source that appears quadratically in the wave equation. We consider both Gaussian sources and explicit trispectrum templates. We attribute the lack of chirality of the low-frequency tail to the fact that, on large scales, gravitational wave generation is almost equally inefficient for both helicities.
