Sigurdur Helgason (mathematician)

Sigurður Helgason
Sigurður Helgason
Born	1927 (1927) (age 90) Akureyri, Iceland
Occupation	Mathematician
Awards	Leroy P. Steele Prize (1988)

Sigurður Helgason (born 1927) is an Icelandic-American mathematician whose research has been devoted to the geometry and analysis on symmetric spaces. In particular he has used new integral geometric methods to establish fundamental existence theorems for differential equations on symmetric spaces as well as some new results on the representations of their isometry groups. He also introduced a Fourier transform on these spaces and proved the principal theorems for this transform, the inversion formula, the Plancherel theorem and the analog of the Paley–Wiener theorem.

He was born in Akureyri, Iceland. In 1954 he earned a PhD from Princeton University under Salomon Bochner. Since 1965, Helgason has been a professor of mathematics at the Massachusetts Institute of Technology.

He was winner of the 1988 Leroy P. Steele Prize for Seminal Contributions for his books Groups and Geometric Analysis and Differential Geometry, Lie Groups and Symmetric Spaces. This was followed by the 2008 book Geometric Analysis on Symmetric Spaces. On May 31, 1996 Helgason received an honorary doctorate from the Faculty of Science and Technology at Uppsala University, Sweden.

He has been a fellow of the American Academy of Arts and Sciences since 1970. In 2012 he became a fellow of the American Mathematical Society.