第六讲超弦理论与宇宙学的挑战

超弦理论从根本上改变了人们对时空的看法，时空在弦论中只是一种宏观体现．弦论中的非经典时空影响早期宇宙的发展，在一些观测宇宙学的实验中人们也许会发现弦论的效应，例如微波背景辐射的功率谱的反常．最近发现的暗能量也对弦论宇宙学提出了挑战．

Challenges in string theory and cosmology

Space-time has become an emergent concept in string theory, but we still lack a fundamental formulation of string theory in a time dependent background. String effects may possibly be first discovered in certain experiments in observational cosmology, such as the power spectrum measurements of the cosmic microwave background. The newly discovered dark energy may constitute the most important challenge to string theory.