# Lie path dependent factor

by lennyleonard
Tags: dependent, factor, path
 P: 24 Hi everyone!! I can't figure out why electromagnetism is defined a non integrable phase factor (or path dependent), referring to the element of the Lie group U1 to which it (the phase factor) belongs. Why it's said to be non-integrable? And, precisely, how do we specify a path for the $e^{\theta}$ ? By parametrizing a path with respect to $\theta$? Thanks!!