That makes a lot of sense, too. So basically by flipping the direction of the "dipping" portion of the contour you make the two equivalent. Makes much more sense now, thanks!
Okay, I think I get it now after thinking about it some more:
So the integral $$\int_{-\infty}^{\infty}{f(p) dp}$$ can be closed above the p-axis by adding a term (and subtracting off the same term to make sure the integral remains unchanged): $$\int_{-\infty}^{\infty}{f(p) dp} =...
So, please correct me if I'm wrong, but it seems to me that by writing: $$ \int_{-\infty}^{\infty}{f(p)dp} = \int_{-\infty}^{\infty}{f(p)dp} + \lim_{r\rightarrow\infty}\int_{0}^{\pi}{f(re^{i\theta})ire^{i\theta}d\theta} +...
1. I'm having some trouble with some of the contour integrals covered in Chapter 2 of Peskin & Schroeder's Intro to QTF. I'm not so much as looking for answers to the integral (in fact, the answers are given in the textbook), but I was hoping someone could point me to some resources to use to...