Chen Xingang, Loeb Abraham, Xianyu Zhong-Zhi
Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, Massachusetts 02138, USA.
Department of Physics, Harvard University, 17 Oxford Street, Cambridge, Massachusetts 02138, USA.
Phys Rev Lett. 2019 Mar 29;122(12):121301. doi: 10.1103/PhysRevLett.122.121301.
Massive fields in the primordial Universe function as standard clocks and imprint clock signals in the density perturbations that directly record the scale factor of the primordial Universe as a function of time, a(t). A measurement of such signals would identify the specific scenario of the primordial Universe in a model-independent fashion. In this Letter, we introduce a new mechanism through which quantum fluctuations of massive fields function as standard clocks. The clock signals appear as scale-dependent oscillatory signals in the power spectrum of alternative scenarios to inflation.
原初宇宙中的大质量场充当标准时钟，并在密度涨落中留下时钟信号，这些信号直接记录了原初宇宙的标度因子随时间的变化关系a(t)。对这类信号的测量将以一种与模型无关的方式确定原初宇宙的具体情形。在本快报中，我们引入了一种新机制，通过该机制，大质量场的量子涨落充当标准时钟。在暴胀替代模型的功率谱中，时钟信号表现为与尺度相关的振荡信号。
