This monograph represents the culmination of a long journey upon which I first embarked a decade ago in 1997. It was after the first term of my junior year at California Institute of Technology that I realized that my true passion was in theoretical physics and not in chemistry or medicine. I switched to becoming a physics major instead, and I had the good fortune of having John Schwarz as my new undergraduate advisor. Given how I first became fascinated with physics after reading a copy of Hyperspace by Michio Kaku way back in high school, I could not wait to jump on the chance then of taking Ph 205 and Ph 239 on Quantum Field Theory and General Relativity as a brand-new, wide-eyed physics major.