On the 1965 Nobel Prize in Physics to Feynman, Schwinger and Tomonaga

Abstract

Already as a young man Gunnar Källén established himself as the leading expert in Sweden in the area of quantum electrodynamics. With an astonishing speed, he became a world expert in this most advanced and difficult domain of theoretical physics of that time. His distinguished four years older collaborator, Arthur Wightman, expressed it with the words:

“At that time I was trying to puzzle out the grammar of the language of quantum field theory, and here was Källén already writing poetry in the language”.

Steven Weinberg, while visiting Stockholm in connection with an “Oskar Klein Lecture” said to me (CJ) that he considered himself as a student of Källén and learned his field theory from him. He said that he had come to Copenhagen taking with him the book of Heitler to learn field theory. But he hardly had opened the book as Källén was nearby acting as his teacher (see Chap. 61).