标题： 轴子等曲率 collider 显示英文标题

标题： Axion Isocurvature Collider

摘要： 宇宙对撞机能够保存来自极高能量尺度相互作用的信息，并将其印记在宇宙可观测量上。通过取宇宙扰动双谱的压缩极限，中间粒子的信息可以直接从观测（如宇宙微波背景 CMB）中提取出来。因此，宇宙对撞机可以成为测试理论模型的强大而有前景的工具。 本文研究了极轻轴子（包括QCD轴子和类轴子粒子），并考虑它们在晚期构成冷暗物质（CDM）。我们关注由这些轴子引起的膨胀型等曲率模，并试图弄清楚轴子扰动如何表现为等曲率对撞机。我们给出了一个中间粒子为玻色子的例子，并表明在压缩极限下，有可能提供具有显著幅度且具有特征角依赖性的时钟信号。这为贡献和分析等曲率双谱的时钟信号提供了一个渠道，我们有望在未来实验中看到这些信号。 显示英文摘要

摘要： Cosmological colliders can preserve information from interactions at very high energy scale, and imprint them on cosmological observables. Taking the squeezed limit of cosmological perturbation bispectrum, information of the intermediate particle can be directly extracted from observations such as cosmological microwave background (CMB). Thus cosmological colliders can be powerful and promising tools to test theoretical models. In this paper, we study extremely light axions (including QCD axions and axion-like-particles), and consider them constituting cold dark matter (CDM) at late times. We are interested in inflationary isocurvature modes by such axions, and try to figure out how axion perturbations can behave as isocurvature colliders. We work out an example where the intermediate particle is a boson, and show that, in the squeezed limit, it is possible to provide a clock signal of significant amplitudes, with a characteristic angular dependence. This provides a channel to contribute and analyze clock signals of isocurvature bispectrum, which we may hopefully see in future experiments.