Is it possible to provide a brief discussion of picture changing operators in string theory in here? If possible then it will be nice to have a discussion of it with some references! Thank you!
closed as not a real question by dmckee♦ Jul 22 '11 at 3:11
It's difficult to tell what is being asked here. This question is ambiguous, vague, incomplete, overly broad, or rhetorical and cannot be reasonably answered in its current form. For help clarifying this question so that it can be reopened, see the FAQ.