Leonida Tonelli

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Leonida Tonelli
Leonida Tonelli.jpg
Born (1885-04-19)19 April 1885
Gallipoli, Apulia, Italy
Died 12 March 1946(1946-03-12) (aged 60)
Pisa, Italy
Nationality Italian
Fields Mathematics
Institutions University of Cagliari
University of Parma
University of Bologna
University of Pisa
Scuola Normale Superiore
Alma mater University of Bologna
Doctoral advisor Cesare Arzelà
Doctoral students Lamberto Cesari, Guido Stampacchia
Known for Tonelli's theorem

Leonida Tonelli (19 April 1885 – 12 March 1946) was an Italian mathematician, noted for creating Tonelli's theorem, a variation of Fubini's theorem, and for introducing semicontinuity methods as a common tool for the direct method in the calculus of variations.[1]

Work[edit]

He is one of the founders of Modern Theory of Functions of Real Variables and his work on the Calculus of Variations is a milestone in analysis.[2]

The present writer's father, W. H. Young, used to recall that this very question — what principle can we use as the foundation of the calculus of variations[3] — had been put him by a young Italian mathematician. His reply was a question: "Can you use semicontinuity?" The young Italian was Leonida Tonelli. Semicontinuity was then still a recent concept, known only to a few. In the hands of Tonelli, it became an important tool in a fundamental new approach to the calculus of variations.

See also[edit]

Notes[edit]

  1. ^ Leonida Tonelli.
  2. ^ The quote is reported verbatim, including the uppercase emphasis on the mathematical topics cited.
  3. ^ As also recalled by Sneddon (1986, p. 36).

Biographical references[edit]

References[edit]

External links[edit]

O'Connor, John J.; Robertson, Edmund F., "Leonida Tonelli", MacTutor History of Mathematics archive, University of St Andrews .