autonne
Autonne is primarily known as the surname of the French mathematician Eugène Autonne, whose work contributed to early 20th‑century matrix theory and functional analysis. The name is attached to a canonical result in linear algebra that bears his name alongside Teiji Takagi: the Autonne–Takagi factorization.
The Autonne–Takagi factorization describes how any complex symmetric matrix can be decomposed in a unitary-congruent form.
In practice, the Autonne–Takagi factorization is used in various areas of applied mathematics, physics, and engineering,
Biographical information on Eugène Autonne is relatively sparse in standard references, but his name endures in