Gabriel Andrew Dirac

Gabriel Andrew Dirac
Born	(1925-03-13)March 13, 1925
Died	July 20, 1984(1984-07-20) (aged 59)
Education	Ph.D.
Alma mater	University of London
Known for	Graph theory
Scientific career
Fields	Mathematics
Institutions	University of Aarhus, Trinity College Dublin
Doctoral advisor	Richard Rado

Gabriel Andrew Dirac (13 March 1925 – 20 July 1984) was a mathematician who mainly worked in graph theory. He stated a sufficient condition for a graph to contain a Hamiltonian circuit. In 1951 he conjectured that n points in the plane, not all collinear, must span at least [n/2] two-point lines, where [x] is the largest integer not exceeding x. This conjecture is still open.

Education

Dirac received his Ph.D. in 1952 from the University of London under Richard Rado.

Career

Dirac was professor of mathematics in the University of Aarhus in Denmark, and was also Erasmus Smith's Professor of Mathematics (1962) at Trinity College Dublin in the mid-1960s.

Family

He was the stepson of Paul Dirac, who adopted him after marrying his mother Manci, and the nephew of Eugene Wigner. His biological father is Richard Balazs, and he has an older sister, and two younger half-sisters.

See also

• Dirac's theorem on Hamiltonian cycles
• Dirac's theorem on chordal graphs
• Dirac's theorem on cycles in k-connected graphs

References

• L. Døvling Andersen, I. Tafteberg Jakobsen, C. Thomassen, B. Toft, and P. Vestergaard (eds.), Graph Theory in Memory of G.A. Dirac, North-Holland, 1989. ISBN 0-444-87129-2.