标题： 弦早期宇宙的动力学拓扑变化、紧致化和波 显示英文标题

标题： Dynamical Topology Change, Compactification and Waves in a Stringy Early Universe

摘要： 精确的弦解被给出，其中模场随时间变化。 它们提供了拓扑结构发生变化的例子。 一些其他的解给出了宇宙学例子，其中某些维度动态紧致化或者模拟了大爆炸之前的场景。 从有效理论的适用区域及其如何结合的角度，得出了一些结论，并利用弦信息，在几何和拓扑结构从低能视角来看尚不清楚的区域进行了分析。 还介绍了其他无尺度层次的时间相关解。 这类解的动力学性质有本质上的不同，类似于平面引力波。 E. Kiritsis 在1994年6月2日至4日巴黎天文台举办的第二届宇宙学日会议上所做的报告。 显示英文摘要

摘要： Exact string solutions are presented, where moduli fields are varying with time. They provide examples where a dynamical change of the topology of space is occurring. Some other solutions give cosmological examples where some dimensions are compactified dynamically or simulate pre-big bang type scenarios. Some lessons are drawn concerning the region of validity of effective theories and how they can be glued together, using stringy information in the region where the geometry and topology are not well defined from the low energy point of view. Other time dependent solutions are presented where a hierarchy of scales is absent. Such solutions have dynamics which is qualitatively different and resemble plane gravitational waves. Talk presented by E. Kiritsis in the 2\`eme Journ\'ee Cosmologie, Observatoire de Paris, 2-4 June 1994.