nLab Gruppenpest

Idea

In the late 1920s, Eugene Wigner and Hermann Weyl highlighted the role that group theory and representation theory play in the analysis of quantum mechanics, for instance in the analysis of atomic spectra. While many applications of groups and their representations to quantum physics had more or less explicitly been observed before, Wigner and Weyl stood out as making the mathematical formalism fully explicit. This attitude was not well received by some of their colleagues, who felt that this formal mathematics had no place in physics. In particular Erwin Schrödinger is said (Wigner (1981)) to have spoken of the Gruppenpest (German for “plague of group theory”) which ought to be abandoned.

In his autobiography John Slater, an MIT physicist, claimed:

It was at this point that Wigner, Hund, Heitler, and Weyl entered the picture with their “Gruppenpest”: the pest of the group theory… The authors of the “Gruppenpest” wrote papers which were incomprehensible to those like me who had not studied group theory, in which they applied these theoretical results to the study of the many electron problem. The practical consequences appeared to be negligible, but everyone felt that to be in the mainstream one had to learn about it. Yet there were no good texts from which one could learn group theory. It was a frustrating experience, worthy of the name of a pest.

I had what I can only describe as a feeling of outrage at the turn which the subject had taken…

As soon as this [Slaters] paper became known, it was obvious that a great many other physicists were as disgusted as I had been with the group-theoretical approach to the problem. As I heard later, there were remarks made such as “Slater has slain the ‘Gruppenpest’”. I believe that no other piece of work I have done was so universally popular.

Eventually this resistance vanished and turned into its opposite in theoretical fundamental physics: in the classification of fundamental particles by unitary representations of the Poincaré group introduced by Hermann Weyl, in the description of gauge theory in terms of associated bundles given by representations of gauge groups. Today almost the first thing that one wants to know about a physical theory is its gauge group and the representations of it that play a role.

References

A transcript of an interview with Wigner where he mentions Schrödinger’s remark on the Gruppenpest is here:

• Interview with Eugene Wigner by Lillian Hoddeson, Gordon Baym and Frederick Seitz at the New Yorker Hotel January 24, 1981 (Niels Bohr Library and Archives)

A historical anlysis of Wigner’s work on group theory with a remark on the Gruppenpest comment is in

• Arianna Borrelli and Bretislav Friedrich, Eugene Wigner and the bliss of the “Gruppenpest” (pdf)

For scholarship on Weyl’s work on group theory and quantum mechanics, see

• Erhard Scholz, 2008, Weyl entering the ‘new’ quantum mechanics discourse. In C. Joas, C. Lehner, J. Renn (eds.). HQ-1: Conference on the History of Quantum Physics (Berlin July 2–6, 2007), Preprint MPI History of Science Berlin, 350 vol. II, 253–271.

• Erhard Scholz, 2006. Introducting groups into quantum theory (1926–1930), Historia Mathematica 33:440–490, arxiv.org/math.HO/0409571.

• Christophe Eckes, Weyl and the mathematisation of Quantum Mechanics individual and collective perspectives, (slides).

• John Slater, Solid-State and Molecular Theory: A Scientific Biography, Wiley (1975) [archive]

  (in the context of solid state physics and molecular theory)