G. H. Hardy

Professor Godfrey Harold Hardy FRS (February 7, 1877 – December 1, 1947) was a prominent British mathematician, known for his achievements in number theory and mathematical analysis.

Non-mathematicians know him for two things:

• A Mathematician's Apology, his essay from 1940 on the aesthetics of mathematics (ISBN 0521427061) with some personal content — which may be the layman's best insight into the mind of a working mathematician.
• His relationship as mentor from 1914 on of the Indian mathematician Srinivasa Ramanujan, whose extraordinary albeit untutored brilliance he almost immediately recognized. Hardy and Ramanujan became close friends and colleagues. In an interview by Paul Erdős, when Hardy was asked what his greatest contribution to mathematics was, Hardy unhesitatingly replied that it was the discovery of Ramanujan. He called their collaboration "the one romantic incident in my life."

After his schooling at Winchester, Hardy entered Cambridge after standing fourth in the Tripos examination. Years later, Hardy sought to abolish the Tripos system as he felt that it was becoming more an end in itself than being a means to an end. While at university, Hardy joined the Cambridge Apostles, an elite, intellectual secret society.

Hardy is credited with reforming British mathematics by bringing rigour into it, which was previously a characteristic of French, Swiss and German mathematics. British mathematicians remained largely in the tradition of applied mathematics, in thrall to the reputation of Isaac Newton; Hardy was in tune with the cours d'analyse methods dominant in France, and aggressively promoted his conception of pure mathematics, in particular against the hydrodynamics which was an important part of Cambridge mathematics.

Hardy was Sadleirian Professor at Cambridge from 1931 to 1942; he had left Cambridge to take the Savilian Chair of Geometry at Oxford in the aftermath of the Bertrand Russell affair during World War I. From 1911 he collaborated with J.E. Littlewood, in extensive work in mathematical analysis and analytic number theory. This led (along with much else) to quantitative progress on the Waring problem, as part of the Hardy-Littlewood circle method, as it became known. In prime number theory they proved results and some notable conditional results also. This was a major factor in the development of number theory as a system of conjectures; examples are the first and second Hardy-Littlewood conjectures.

Hardy is also known for formulating the Hardy-Weinberg principle, a basic principle of population genetics, independently from Wilhelm Weinberg in 1908. He played cricket with the geneticist Reginald Punnett who introduced the problem to him, and Hardy thus became the somewhat unwitting founder of a branch of applied mathematics.

Socially he was associated with the Bloomsbury group and the Cambridge Apostles and was an avid cricket fan. He was an atheist, and, according to those who knew him best, rather frank about being a non-practising homosexual (Littlewood's phrase). Hardy never married, and in his final years he was cared for by his sister.

See also

• Course of Pure Mathematics
• A Mathematician's Apology
• Hardy space
• Pisot-Vijayaraghavan number

Publications

• Hardy G.H. (1940) A Mathematician's Apology Cambridge University Press: London.
• Hardy G.H. (1940) Ramanujan Cambridge University Press: London.
• Hardy G.H. and E.M. Wright (1938) An Introduction to the Theory of Numbers (current edition ISBN 0198531710)
• Hardy G.H. (1908) A Course of Pure Mathematics

External link

• Quotations of G. H. Hardy