Lecture 23 Jan

These are my lecture notes for 23 Jan.

The related chapter Z-bach, Ch.7, is a discussion of worldsheet coordinate parametrization for the relativistic string. In particular, the worldsheet spatial coordinate sigma is chosen according to two criteria:

1. that sigma be perpendicular to the worldsheet time coordinate tau, and
2. that the energy density of the string dE/d(sigma) be constant in this parametrization.

PS: Here is an older set of notes on the Noether and Goldstone Theorems (from my graduate Quantum Field Theory course of a few years ago). These notes contain a pretty clear discussion of Noether’s Theorem and also Goldstone’s Theorem, in the context of relativistic field theories. YMMV, but I hope you find these notes helpful.