Marcel Grossmann (born in Budapest on April 9th, 1878 - died in Zurich on September 7th, 1936) was a mathematician and a friend and classmate of Albert Einstein. He became a teacher at ETH, specialising in descriptive geometry

It was Grossmann who emphasized the importance of the Riemannian geometry to Einstein, which was a necessary step in the development of Einstein's general theory of relativity.

The community of relativists celebrates Grossmann's contributions to physics by organizing Marcel Grossman meetings every year.

Reference

• A. Einstein and M. Grossmann. Entwurf einer verallgemeinerten relativitatstheorie und einer theorie der gravitation. Zeitschrift fur Mathematik und Physik, 62:225, 1914.