论文标题
随机重力波各向异性中的原始时钟
Primordial Clocks within Stochastic Gravitational Wave Anisotropies
论文作者
论文摘要
早期宇宙中的一阶相变可以提供可观察到的随机重力背景（SGWB），该背景必然在天空中具有原始各向异性。在多场通货膨胀的情况下，这些各向异性可能具有与绝热波动截然不同的显着等化成分，这为高能物理学在通货膨胀尺度下提供了替代的发现通道。在这里，我们考虑在通货膨胀期间经典地振荡重场，可以在原始各向异性的功率谱系中烙印出独特的尺度不变特征。尽管这种特征在宇宙微波背景中受到高度限制，但我们表明它们的幅度在同化SGWB中可以观察到很大，尽管两者都探测了相似的通货膨胀时期。测量SGWB在所需级别上，$ \ ell \ sim {\ cal o}（10-100）$在技术上具有挑战性。但是，我们期望早期检测强的各向同性SGWB，并且对各向异性的保证将刺激具有足够敏感性，角度分辨率和前景歧视的下一代探测器的发展。
A first-order phase transition in the early universe can give an observable stochastic gravitational background (SGWB), which will necessarily have primordial anisotropies across the sky. In multi-field inflationary scenarios, these anisotropies may have a significant isocurvature component very different from adiabatic fluctuations, providing an alternate discovery channel for high energy physics at inflationary scales. Here, we consider classically oscillating heavy fields during inflation that can imprint distinctive scale-invariance-breaking features in the power spectrum of primordial anisotropies. While such features are highly constrained in the cosmic microwave background, we show that their amplitude can be observably large in isocurvature SGWB, despite both probing a similar period of inflation. Measuring SGWB multipoles at the required level, $\ell \sim {\cal O}(10-100)$, will be technologically challenging. However, we expect that early detection of a strong isotropic SGWB, and the guarantee of anisotropies, would spur development of next-generation detectors with sufficient sensitivity, angular resolution, and foreground discrimination.
