About Ernst Sigismund Fischer
Lived 1875 – 1954 (aged 79). Ernst Sigismund Fischer was an Austrian mathematician and university teacher, known for Fischer's inequality and Riesz–Fischer theorem.
Ernst Sigismund Fischer (12 July 1875 – 14 November 1954) was a mathematician born in Vienna, Austria. He worked alongside Franz Mertens and Hermann 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.
He is the grandson of composer Karl Graedener.
Don’t just read it —
keep it.
Full-length biographies made to live with: read them, listen on the way to work, watch them tonight.
- E-book
- Audio
- Video
Instant download · yours to keep · every purchase keeps this site free
Important facts
People in Ernst Sigismund Fischer's life
Named in this biography and alive at the same time
Related people
Same field, nearest in time
Contemporaries
People whose lives overlapped Ernst Sigismund Fischer's
Frequently asked questions
Who was Ernst Sigismund Fischer?
Austrian mathematician (1875–1954)
When was Ernst Sigismund Fischer born?
Ernst Sigismund Fischer was born on 12 July 1875 in Vienna.
When did Ernst Sigismund Fischer die?
Ernst Sigismund Fischer died on 14 November 1954 in Cologne.
What was Ernst Sigismund Fischer's occupation?
Ernst Sigismund Fischer was a mathematician and university teacher.
What was Ernst Sigismund Fischer known for?
Ernst Sigismund Fischer was known for Fischer's inequality and Riesz–Fischer theorem.
What nationality was Ernst Sigismund Fischer?
Ernst Sigismund Fischer was Austrian.
Sources & further reading
· Wikipedia: Ernst Sigismund Fischer
· DBpedia: Ernst Sigismund Fischer
Cite this page
APA: Biography.guide. (2026). Ernst Sigismund Fischer. https://biography.guide/ernst-sigismund-fischer/
MLA: "Ernst Sigismund Fischer." Biography.guide, https://biography.guide/ernst-sigismund-fischer/.
Chicago: "Ernst Sigismund Fischer." Biography.guide. https://biography.guide/ernst-sigismund-fischer/.
Data last updated: 2026-09-23 · Spot an error? Report a correction.
Portrait: Wikimedia Commons · author & licence
Page generated 2026-09-27 05:06 UTC