Ernst Sigismund Fischer
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Ernst Sigismund Fischer (July 12, 1875 - November 14, 1954) was born in Vienna, Austria. He worked alongside both Mertens and Minkowski at the Universities of Vienna and Zurich, respectively. He later became professor at the University of Erlangen, where he worked with Emmy Noether.
His main area of research was mathematical analysis, specifically orthonormal sequences of functions which laid groundwork for the emergence of the concept of a Hilbert space.
The Riesz-Fischer theorem in Lebesgue integration is named in his honour.
[edit] External links
- O'Connor, John J. & Robertson, Edmund F., “Ernst Sigismund Fischer”, MacTutor History of Mathematics archive