Srinivasa Ramanujan (born 22 December 1887 – died 26 April 1920) born Srinivasa Ramanujan Aiyangar, was an Indian mathematician. Though he had almost no formal training in pure mathematics, he made substantial contributions to mathematical analysis, number theory, infinite series, and continued fractions, including solutions to mathematical problems then considered unsolvable.
Ramanujan married a nine-year-old girl:
The third historical figure is the great Indian mathematical genius, Srinivasa Ramanujan, who was born in 1887 and died some 32 years later. At age 22, he married 9-year-old Srimathia Janki, who brought her mother with her when she moved into his household (Kolata, 1987).
Bullough V.L. (1990). “History in adult human sexual behavior with children and adolescents in Western societies”, in Pedophilia: Biosocial Dimensions (Jay R. Feierman, ed.). New York: Springer-Verlag Publishers, p. 71.