Cuthbert Edmund Cullis (15 April 1868 – 20 March 1954) was an English mathematician who worked as a professor of mathematics at the University of Calcutta and was influential in standardizing notation and conventions in the algebra of matrices and determinants.
Cullis was the son of Frederick John, a dock surveyor in Gloucester and Louisa (née Corbett) Cullis. One of his two sisters, Winifred C. Cullis, became a physiologist. He was educated at King Edward High School, Birmingham after which he joined Caius College, Cambridge. After being seventh wrangler in 1891 he went to Jena, Germany and received a doctorate under Carl Johannes Thomae with a thesis titled Die Bewegung Durchlöcherter Körper in einer Inkompressiblen Flüssigkeit. He became a lecturer at Hartley College and moved to the University of Calcutta in 1910 where he served as Hardinge Professor of Mathematics until his retirement in 1925.[1]
Cullis published extensively in the Bulletin of the Calcutta Mathematical Society and among his contribution was the work demonstrating that the Moebius ring was a section of the cubic surface defined by:
y(x2+y2+z2-a2)-2z(x2+y2+ax)=0
His most important work was Matrices and Determinoids (1913-1925) to be published in three volumes although only two volumes and a part of the third volume were finally published. He defined what is now called the Cullis-Radić determinant for rectangular matrices.[2] [3]
Cullis died in Gloucester and bequeathed £1000 to Gonville & Caius college to support needy students.[4]