论文标题
Bose-Einstein冷凝物中的弯曲和扩展的时空几何形状
Curved and expanding spacetime geometries in Bose-Einstein condensates
论文作者
论文摘要
声子具有无质量相对论粒子的特征线性分散关系。它们是作为玻色烯恒定冷凝物的低能量激励而产生的，在非均匀情况下，它们受到空间和时间依赖性的声学度量的控制。我们讨论如何在实验上设计该度量，以实现弯曲的时空几何形状，特别是扩展了Friedmann-Lema-Robertson-Walker-Walker宇宙学，具有负，消失或正空间曲率。可以通过背景凝结物的时间依赖散射长度获得非呈现的哈勃速率。对于相对论量子场，这导致了粒子产生的现象，我们会详细描述。我们解释了如何根据实验可访问的相关函数来测试曲线时空中量子场理论的粒子产生和其他有趣的特征。
Phonons have the characteristic linear dispersion relation of massless relativistic particles. They arise as low energy excitations of Bose-Einstein condensates and, in nonhomogeneous situations, are governed by a space- and time-dependent acoustic metric. We discuss how this metric can be experimentally designed to realize curved spacetime geometries, in particular, expanding Friedmann-Lemaître-Robertson-Walker cosmologies, with negative, vanishing, or positive spatial curvature. A nonvanishing Hubble rate can be obtained through a time-dependent scattering length of the background condensate. For relativistic quantum fields this leads to the phenomenon of particle production, which we describe in detail. We explain how particle production and other interesting features of quantum field theory in curved spacetime can be tested in terms of experimentally accessible correlation functions.
