Chä Seok-Yeong, Fischer Uwe R
Seoul National University, Department of Physics and Astronomy, Center for Theoretical Physics, Seoul 08826, Korea.
Phys Rev Lett. 2017 Mar 31;118(13):130404. doi: 10.1103/PhysRevLett.118.130404. Epub 2017 Mar 30.
We consider an analogue de Sitter cosmos in an expanding quasi-two-dimensional Bose-Einstein condensate with dominant dipole-dipole interactions between the atoms or molecules in the ultracold gas. It is demonstrated that a hallmark signature of inflationary cosmology, the scale invariance of the power spectrum of inflaton field correlations, experiences strong modifications when, at the initial stage of expansion, the excitation spectrum displays a roton minimum. Dipolar quantum gases thus furnish a viable laboratory tool to experimentally investigate, with well-defined and controllable initial conditions, whether primordial oscillation spectra deviating from Lorentz invariance at trans-Planckian momenta violate standard predictions of inflationary cosmology.
我们考虑一个处于膨胀的准二维玻色-爱因斯坦凝聚体中的类德西特宇宙，其中超冷气体中的原子或分子之间存在占主导地位的偶极-偶极相互作用。结果表明，暴胀宇宙学的一个标志性特征，即暴胀子场关联功率谱的标度不变性，在膨胀初始阶段激发谱呈现出旋子极小值时会经历强烈修正。因此，偶极量子气体提供了一个可行的实验工具，在定义明确且可控的初始条件下，研究在跨普朗克动量下偏离洛伦兹不变性的原初振荡谱是否违反暴胀宇宙学的标准预测。
