低能有效 Hamilton 量的微扰构造
一个多体 Hamilton 量经常难以严格求解, 但一般来说, 凝聚态物理更关心基态附近一个较低能量范围内发生的事情. 实用的原因是凝聚态系统所处的温度往往低于系统内禀的其他能量尺度, 例如 Fermi 能; 理论上的原因是所谓 “低能有效理论” 往往能 “演生” 出一些新奇而普适的特性, 新奇是指和理论的微观构造没有明显的相似性, 普适是指对微观细节的依赖较少, 微观上截然不同的系统在大尺度下看来可能是相似的.
Connections in physics
Modern differential geometry provides a unified picture for different aspects of physics. In this blog article I would like to introduce three kinds of physical subjects relating to connection on a fibre bundle, namely gauge field, general relativity and theory of quantum Hall effect. The ‘gauge field’ part is among the appendices of my undergraduate thesis.
37 post articles, 5 pages.