August 7th, 2011

beartato phd

(no subject)

I think I finally grasped some of what's going on in the "Baby Problem" (!) in chapter I.7 of Zee's book on QFT. It's been a long, slow process coming to grips with this material. I think I first encountered the book some years ago near the middle-end of grad school.

Anyway, here's some notes I wrote up about it, containing pretty pictures like the following:

I'm still pretty weirded out by the fact that I innocently changed the x^4 in his problem as stated into a x^3, and worked out the whole thing, and only noticed after I was all done that the integral can't possibly converge with an odd polynomial like x^3. It's so weird how the graph theory doesn't seem that different with vertices of even rather than odd degree, but the algebra/calculus side of things cares a lot.