Английская Википедия:Hazel Perfect

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Шаблон:Short description Hazel Perfect (circa 1927 – 8 July 2015)Шаблон:R was a British mathematician specialising in combinatorics.

Contributions

Perfect was known for inventing gammoids,Шаблон:RШаблон:Ran for her work with Leon Mirsky on doubly stochastic matrices,Шаблон:RШаблон:Ran for her three books Topics in Geometry,Шаблон:RШаблон:Ran Topics in Algebra,Шаблон:RШаблон:Ran and Independence Theory in Combinatorics,Шаблон:RШаблон:Ran and for her work as a translator (from an earlier German translation) of Pavel Alexandrov's book An Introduction to the Theory of Groups (Hafner, 1959).Шаблон:RШаблон:Ran

The Perfect–Mirsky conjecture, named after Perfect and Leon Mirsky, concerns the region of the complex plane formed by the eigenvalues of doubly stochastic matrices. Perfect and Mirsky conjectured that for <math>n\times n</math> matrices this region is the union of regular polygons of up to <math>n</math> sides, having the roots of unity of each degree up to <math>n</math> as vertices. Perfect and Mirsky proved their conjecture for <math>n\le 3</math>; it was subsequently shown to be true for <math>n=4</math> and false for <math>n=5</math>, but remains open for larger values Шаблон:Nowrap

Education and career

Perfect earned a master's degree through Westfield College (a constituent college for women in the University of London) in 1949, with a thesis on The Reduction of Matrices to Canonical Form.Шаблон:R In the 1950s, Perfect was a lecturer at University College of Swansea; she collaborated with Gordon Petersen, a visitor to Swansea at that time, on their translation of Alexandrov's book.Шаблон:R She completed her Ph.D. at the University of London in 1969; her dissertation was Studies in Transversal Theory with Particular Reference to Independence Structures and Graphs.Шаблон:R She became a reader in mathematics at the University of Sheffield.Шаблон:R