At the age of twelve he became fascinated with a fact he found stated in a popular astronomy book, that a body in a circular orbit with period

[1] His Diplom Thesis was written under Pauli in 1938 on higher-spin particles in Dirac theory, presenting his results to the Swiss Physical Society in 1938.

Upon presenting his results, Pauli reportedly said after a few minutes simply, "Das habe ich mir auch so gedach" ("I thought so too").

[1] With few academic jobs available in Switzerland at the outbreak of World War II, Jauch became a part-time teacher at Trogen in Appenzell, where he received an international exchange fellowship to study a Ph.D. at the University of Minnesota on Pólya's recommendation.

During his doctoral studies in Minneapolis, Jauch met Anna Tonette "Tonia" Hegland, a graduate student in the School of Social Work at the University of Minnesota, and the two were married on 1 January 1940.

However, it was extremely difficult to carry out research in Switzerland during the war: as Heinrich Behnke wrote to Erich Hecke in a letter of 8 March 1940, "The Paulis would be very happy if you paid them a visit again [in Zurich].

[5] There Pauli and Jauch studied the magnetic moment of the neutron, as well as the infrared divergence problem using Dirac field theory, reporting their results to the American Physical Society in 1944.

[3] In March 1946, Jauch decided to explore new directions by joining Bell Laboratories in Murray Hill, New Jersey as a research scientist for four months, where he studied luminescence in solids.

[10] Jauch conceived of this book on quantum electrodynamics while on a Fulbright Program research fellowship at Trinity College, Cambridge from 1950 to 1951, and it became noted for its "uncommonly neat and painstaking treatment of details.

In 1958 Jauch and his family returned to Europe, where he spent one year working at CERN (The European Center for Nuclear Research) in Geneva.

While giving a lecture at CERN on the impossibility of hidden variables in 1963, Jauch met John Stewart Bell, with whom he had "some intense discussion".

[13] Indeed, in his famous paper of 1964 on hidden variables, Bell writes of Gleason's theorem, "I am much indebted to Professor Jauch for drawing my attention to this work.

Among his doctoral students were Gérard Emch, Marcel André Guenin, Andrew Lenard, Constantin Piron, and Kenneth Watson.