Carl Gottfried Neumann was a German Mathematician, born May 7, 1832 in Königsberg (now Kaliningrad, Russia) and died March 27, 1925 in Leipzig.
Neumann worked on the Dirichlet principle, and can be considered one of the initiators of the theory of integral equations. The Neumann series, which is analogous to the geometric series
but for infinite matrices, is named after him.
Together with Alfred Clebsch he founded the mathematical research journal Mathematische Annalen.
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