Richard A. Parker (29 January 1953 – 26 January 2024) was a mathematician and freelance computer programmer born in

Surrey Surrey () is a Ceremonial counties of England, ceremonial county in South East England. It is bordered by Greater London to the northeast, Kent to the east, East Sussex, East and West Sussex to the south, and Hampshire and Berkshire to the wes ...

who lived for much of his life in

Cambridge Cambridge ( ) is a List of cities in the United Kingdom, city and non-metropolitan district in the county of Cambridgeshire, England. It is the county town of Cambridgeshire and is located on the River Cam, north of London. As of the 2021 Unit ...

England England is a Countries of the United Kingdom, country that is part of the United Kingdom. It is located on the island of Great Britain, of which it covers about 62%, and List of islands of England, more than 100 smaller adjacent islands. It ...

. He invented many of the algorithms for computing the modular character tables of finite

simple group SIMPLE Group Limited is a conglomeration of separately run companies that each has its core area in International Consulting. The core business areas are Legal Services, Fiduciary Activities, Banking Intermediation and Corporate Service. The d ...

s. He discovered the relation between Niemeier lattices and deep holes of the

Leech lattice In mathematics, the Leech lattice is an even unimodular lattice Λ24 in 24-dimensional Euclidean space which is one of the best models for the kissing number problem. It was discovered by . It may also have been discovered (but not published) by Er ...

, and constructed Parker's

Moufang loop In mathematics, a Moufang loop is a special kind of algebraic structure. It is similar to a group in many ways but need not be associative. Moufang loops were introduced by . Smooth Moufang loops have an associated algebra, the Malcev algebra, ...

of order 2¹³ (which was used by

John Horton Conway John Horton Conway (26 December 1937 – 11 April 2020) was an English mathematician. He was active in the theory of finite groups, knot theory, number theory, combinatorial game theory and coding theory. He also made contributions to many b ...

in his construction of the

monster group In the area of abstract algebra known as group theory, the monster group M (also known as the Fischer–Griess monster, or the friendly giant) is the largest sporadic simple group; it has order : : = 2463205976112133171923293 ...

Books

* Conway, J. H.; Sloane, N. J. A. (1999). ''Sphere packings, lattices and groups.'' (3rd ed.) With additional contributions by E. Bannai, R. E. Borcherds, John Leech, Simon P. Norton, A. M. Odlyzko, R. A. Parker, L. Queen and B. B. Venkov. Grundlehren der Mathematischen Wissenschaften, 290. New York: Springer-Verlag. . * *''An Atlas of Brauer Characters'' (London Mathematical Society Monographs) by Christopher Jansen, Klaus Lux, Richard Parker, Robert Wilson. Oxford University Press, U.S. (October 1, 1995)

References

Alumni of St John's College, Cambridge 20th-century English mathematicians 21st-century English mathematicians Group theorists 1953 births Living people {{UK-mathematician-stub