Charles R. Leedham-Green is a retired professor of

mathematics Mathematics is an area of knowledge that includes the topics of numbers, formulas and related structures, shapes and the spaces in which they are contained, and quantities and their changes. These topics are represented in modern mathematics ...

Queen Mary, University of London , mottoeng = With united powers , established = 1785 – The London Hospital Medical College1843 – St Bartholomew's Hospital Medical College1882 – Westfield College1887 – East London College/Queen Mary College , type = Public researc ...

, known for his work in

group theory In abstract algebra, group theory studies the algebraic structures known as group (mathematics), groups. The concept of a group is central to abstract algebra: other well-known algebraic structures, such as ring (mathematics), rings, field ...

. He completed his

DPhil A Doctor of Philosophy (PhD, Ph.D., or DPhil; Latin: or ') is the most common degree at the highest academic level awarded following a course of study. PhDs are awarded for programs across the whole breadth of academic fields. Because it is a ...

at the

University of Oxford , mottoeng = The Lord is my light , established = , endowment = £6.1 billion (including colleges) (2019) , budget = £2.145 billion (2019–20) , chancellor ...

. His parents were John Charles Leedham-Green (1902–1984), a surgeon and general practitioner in

Southwold Southwold is a seaside town and civil parish on the English North Sea coast in the East Suffolk district of Suffolk. It lies at the mouth of the River Blyth within the Suffolk Coast and Heaths Area of Outstanding Natural Beauty. The town is a ...

, and Gertrude Mary Somerville Caldwell.

Work

With Leonard Soicher, Leedham-Green designed the product replacement algorithm; an algorithm within

computational group theory In mathematics, computational group theory is the study of group (mathematics), groups by means of computers. It is concerned with designing and analysing algorithms and data structures to compute information about groups. The subject has attracted ...

that generates random elements of groups by taking a

random walk In mathematics, a random walk is a random process that describes a path that consists of a succession of random steps on some mathematical space. An elementary example of a random walk is the random walk on the integer number line \mathbb Z ...

through the group. This algorithm has been implemented in both GAP and

MAGMA Magma () is the molten or semi-molten natural material from which all igneous rocks are formed. Magma is found beneath the surface of the Earth, and evidence of magmatism has also been discovered on other terrestrial planets and some natural sa ...

. He is responsible for a great body of work in group theory. In recent times, this has involved research in computational group theory and

pro-p group In mathematics, a pro-''p'' group (for some prime number ''p'') is a profinite group G such that for any open normal subgroup N\triangleleft G the quotient group G/N is a ''p''-group. Note that, as profinite groups are compact, the open subgro ...

s. The 300th edition of the ''

Journal of Algebra ''Journal of Algebra'' (ISSN 0021-8693) is an international mathematical research journal in algebra. An imprint of Academic Press, it is published by Elsevier. ''Journal of Algebra'' was founded by Graham Higman, who was its editor from 1964 to 1 ...

'' was dedicated to him for his 65th birthday. On the occasion of his retirement in 2006, the Mathematics Research Centre at Queen Mary held a conference in celebration of his mathematical achievements.

Selected publications

*Charles R. Leedham-Green, Leonard H. Soicher: Collection from the Left and Other Strategies. ''J. Symb. Comput.'' 9(5/6): 665–675 (1990) *Charles R. Leedham-Green, Cheryl E. Praeger, Leonard H. Soicher: Computing with Group Homomorphisms. ''J. Symb. Comput.'' 12(4/5): 527–532 (1991) *Derek F. Holt, C. R. Leedham-Green, E. A. O'Brien and Sarah Rees: Testing Matrix Groups for Primitivity. ''Journal of Algebra'', Volume 184, Issue 3, 15 September 1996, Pages 795–817 *Derek F. Holt, C. R. Leedham-Green, E. A. O'Brien and Sarah Rees: Computing Matrix Group Decompositions with Respect to a Normal Subgroup. ''Journal of Algebra'', Volume 184, Issue 3, 15 September 1996, Pages 818–838. *C. R. Leedham-Green and E. A. O'Brien: Tensor Products are Projective Geometries. ''Journal of Algebra'', Volume 189, Issue 2, 15 March 1997, Pages 514–528 *Robert Beals, Charles R. Leedham-Green, Alice C. Niemeyer, Cheryl E. Praeger, Ákos Seress: Permutations With Restricted Cycle Structure And An Algorithmic Application. ''Combinatorics, Probability & Computing'' 11(5): (2002) *C. R. Leedham-Green and E. A. O'Brien: Recognising tensor-induced matrix groups. ''Journal of Algebra'', Volume 253, Issue 1, 1 July 2002, Pages 14–30 *Nigel Boston and Charles Leedham-Green: Explicit computation of Galois p-groups unramified at p. ''Journal of Algebra'', Volume 256, Issue 2, 15 October 2002, Pages 402–413. *Charles Leedham-Green and Sue McKay: The Structure of Groups of Prime Power Order (2002) *John J. Cannon, Bettina Eick, Charles R. Leedham-Green: Special polycyclic generating sequences for finite soluble groups. ''J. Symb. Comput''. 38(5): 1445–1460 (2004) *Robert Beals, Charles R. Leedham-Green, Alice C. Niemeyer, Cheryl E. Praeger and Ákos Seress: Constructive recognition of finite alternating and symmetric groups acting as matrix groups on their natural permutation modules. ''Journal of Algebra'', Volume 292, Issue 1, 1 October 2005, Pages 4–46 *S.P. Glasby, C.R. Leedham-Green and E.A. O'Brien: Writing projective representations over subfields. ''Journal of Algebra'', Volume 295, Issue 1, 1 January 2006, Pages 51–61 *Isaac Newton, C. R. Leedham-Green (Editor): "The Mathematical Principles of Natural Philosophy: An Annotated Translation of the Principia" (30 September 2019)

References

External links

His homepage
{{DEFAULTSORT:Leedham-Green, Charles Year of birth missing (living people) Living people Group theorists 20th-century British mathematicians 21st-century British mathematicians Place of birth missing (living people) Academics of Queen Mary University of London People from the Scottish Borders