Fritz John

Fritz John (14 June 1910 – 10 February 1994) was a

John published his first paper in 1934 on Morse theory. He was awarded his doctorate in 1934 with a thesis entitled Determining a function from its integrals over certain manifolds from Göttingen. With Richard Courant's assistance he spent a year at St John's College, Cambridge. During this time he published papers on the Radon transform, a theme to which he would return throughout his career.

John was appointed an assistant professor at the University of Kentucky in 1935 and he emigrated to the United States, becoming naturalised in 1941. He stayed at Kentucky until 1946, apart from between 1943 and 1945, during which he did war service for the Ballistic Research Laboratory at the Aberdeen Proving Ground in Maryland. In 1946 he moved to New York University, where he remained for the rest of his career.

Throughout the 1940s and 1950s he continued to work on the Radon transform, in particular its application to linear

From the mid-1950s on, he started working on the theory of equilibrium nonlinear elasticity. He coauthored with Richard Courant the two-volume work Introduction to Calculus and Analysis, first published in 1965. He retired in 1981, but continued to work on nonlinear waves.

Honors

He received many awards during his career including the

• John, Fritz (1955), Plane waves and spherical means applied to partial differential equations, Interscience Tracts in Pure and Applied Mathematics, vol. 2 (1st ed.), New York:
  Zbl 0067.32101. John's famous monograph on the Radon transform and its application to partial differential equations
  .
• John, Fritz (1982), Partial Differential Equations (4th ed.), New York: Springer-Verlag,
  ISBN 0-387-90609-6
  .
• John, Fritz (1985),
  Zbl 0584.01025
  .
• John, Fritz (1985a),
  Zbl 0584.01025
  .

• Bounded mean oscillation
• Fritz John conditions
• John ellipsoid
• John transform

Notes

References

• Klainerman, S. (1998). "On the work and legacy of Fritz John, 1934–1991. Dedicated to the memory of Fritz John".
  doi:10.1002/(sici)1097-0312(199809/10)51:9/10<991::aid-cpa3>3.0.co;2-t
  .
• Moser, Jürgen (1995). "Fritz John, 1910–1994" (PDF). Notices of the AMS. 42 (1): 256–257.
• Vernacchia-Galli, Jole (1986), "Fritz John", Regesto delle lauree honoris causa dal 1944 al 1985, Studi e Fonti per la storia dell'Università di Roma (in Italian), vol. 10, Roma: Edizioni Dell'Ateneo, pp. 823–844. The "regest of honoris causa degrees from 1944 to 1985" (English translation of the title) is a detailed and carefully commented regest of all the documents of the official archive of the Sapienza University of Rome pertaining to the honoris causa degrees, awarded or not. It includes all the awarding proposals submitted during the considered period, detailed presentations of the work of the candidate, if available, and precise references to related articles published on Italian newspapers and magazines, if the laurea was awarded.