"These notes were taken by Brian Hill during Sidney Coleman's lectures on Quantum Field Theory (Physics 253), given at Harvard University in Fall semester of the 1986-1987 academic year. They were recently typeset, edited and reorganized by Bryan Chen and Yuan-Sen Ting. Although most of topics in the second part of the course (Physics 253b) were assembled and published in Coleman's book "Aspects of Symmetry", these notes remain the principal source for the Physics 253a materials."











