Alan Gaius Ramsay McIntosh
Alan Gaius Ramsay McIntosh was an Australian mathematician who dealt with analysis. He was a professor at the Australian National University in Canberra.
McIntosh was born in Sydney, New South Wales on 17 January 1952. He studied at the University of New England with a bachelor's degree in 1962 and PhD in 1966 with Frantisek Wolf at the University of California, Berkeley, for his thesis "Representation of Accretive Bilinear Forms in Hilbert Space by Maximal Accretive Operator ". At Berkeley, he was also a student of Tosio Kato. As a post-doctoral student, he was at the Institute for Advanced Study and from 1967 he taught at Macquarie University, moving to the Australian National University in 1999. In 2014 he became emeritus.
McIntosh was involved in solving the Calderon conjecture in the theory of singular integral operators.
In 2002, he solved with Pascal Auscher, Michael T. Lacey, Philipp Tchamitchian and Steve Hofmann the open Kato root problem for elliptic differential operators.
He also worked on singular integral operators, boundary value problems of partial differential equations with applications, spectral theory and functional calculus of operators in Banach spaces, analysis with Clifford algebras, barriers for the heat kernel equation and functional calculus for elliptic partial differential operators.
In 1986 he became a fellow of the Australian Academy of Science, whose Hannan Medal he received in 2015. In 2002 he received the Moyal Medal from Macquarie University.