This man is the alphabetically earlier namesake of a theorem which evaluates the derivative of an energy eigenvalue of a Hamiltonian with respect to a parameter. This physicist represented solutions to the Dirac equation in (1+1) spacetime dimensions using a checkerboard (10[1])model, which he (10[1])first published in a textbook written with Albert Hibbs. This man's doctoral advisor once postulated to him in a phone call that there only exists one (10[1])electron in the (-5[1])universe. In this physicist's namesake (10[1])formulation of quantum mechanics, (10[1])all possible trajectories are (10[1])integrated to (10[1])compute the amplitude of a process. With Schwinger and Tomonaga, this man won the Nobel prize in physics for his contributions to quantum electrodynamics. For 10 points, antiparticles are read as particles moving backward in (10[1])time in which Caltech physicist's diagrams? (10[1])■END■