膨胀的多重宇宙

安东尼·阿圭雷博士(基础问题研究所科学副总监)在过去的十年中,宇宙学领域内发生了两件令人震惊的大事:一是宇宙学家们建立了一个真实的宇宙学"标准模型".通过结合一系列相对简单的对早期宇宙的猜想和已经证明的引力、核子、等离子和天体物理学知识,该理论能够适用于几乎所有现存的观测数据,并可重复测试和相互校验该模型的基本构成.二是科学家们意识到,通过宇宙膨胀--这一理论原本是为了解释构建"标准模型"所需的宇宙早期情况而提出的--目前所观测到的宇宙可能仅仅是一个巨大、复杂、多元的多重宇宙的"沧海一瞥",毫不足奇.多重宇宙的结构如何?我们所处的宇宙与其他宇宙关系如何?如果根据该理论推导出来诸多属性不一的宇宙,我们将使用哪些属性来与所能观测到的宇宙相互印证,以证明该理论的真伪?这些就是本文中两个主题人物所提出的一部分问题.亚历山大·维兰金(Alexander Vilenkin)是膨胀理论的先驱之一,亦是多重宇宙研究领域的顶尖科学家.理查·伊瑟(Richard Easther)则是一位致力于研究多重宇宙理论中一个最为微妙的方面的年轻科学家.他的研究方向是:如何在清点多重宇宙中的宇宙?

The Inflationary Multiverse

Introduction: Over the past decade, two astonishing things have occurred in the field of cosmology. First, cosmologists have established a true "Standard Model" of cosmology: By combining a relatively simple set of conditions that held at cosmic early times with well-tested gravitational, nuclear, plasma, and astrophysics, the theory is able to accommodate essentially all extant observational data, while providing multiple tests and cross-checks of the model's basic ingredients. Second, it has been realized that through the process of cos-mological inflation--invented to account for the early conditions required by the Standard Model-the observed universe might actually be just one tiny glimpse of a vast, complex and diverse "multiverse." What is the structure of a multiverse? How is our universe related to the others? If the theory produces many regions with different properties, which properties do we compare to our observable universe so as to test the theory? These are some of the many questions asked by the two subjects of this composite article: Alexander Vilenkin, one of inflation theory's pioneers and a leading figure in multiverse research, and Richard Easther, a young scientist focusing on one of the trickiest aspects of the multiverse: How to count the universes in it?