Galois, Evariste (1811–1832)

French mathematician who originated the theory of groups and greatly extended the understanding of the conditions in which an algebraic equation is solvable.

Galois was born near Paris and entered the Ecole Normale Supérieure in 1829. By then he had already mastered the most recent work on the theory of equations, number theory, and elliptic functions, and was in contact with mathematician Augustin Cauchy, but Galois's attempts to gain recognition for his work were thwarted by the French mathematical establishment.

In 1830, Galois joined the revolutionary movement. In the next year he was twice arrested, and was imprisoned for nine months for taking part in a republican demonstration. Shortly after his release he was killed in a duel. The night before, he had hurriedly written out his discoveries on group theory. His only published work was a paper on number theory in 1830.

What has come to be known as the Galois theorem demonstrated the insolubility of higher-than-fourth-degree equations by radicals. Galois theory involved groups formed from the arrangements of the roots of equations and their subgroups, which he fitted into each other rather like Chinese boxes.