A First Course in String Theory
14.2 Generating function for the unoriented bosonic open string theory.
How to add “a term that implements the projection to unoriented states”?
What is the projector? ?
To keep only the odd-power terms, we should construct an odd function:
— Me@2015-09-17 02:27:20 PM
2015.09.23 Wednesday (c) All rights reserved by ACHK