Walter Kurt Hayman FRS (6 January 1926 – 1 January 2020) was a British

mathematician A mathematician is someone who uses an extensive knowledge of mathematics in their work, typically to solve mathematical problems. Mathematicians are concerned with numbers, data, quantity, structure, space, models, and change. History On ...

known for contributions to complex analysis. He was a professor at

Imperial College London Imperial College London (legally Imperial College of Science, Technology and Medicine) is a public research university in London, United Kingdom. Its history began with Prince Albert, consort of Queen Victoria, who developed his vision for a cu ...

Life and work

Hayman was born in

Cologne Cologne ( ; german: Köln ; ksh, Kölle ) is the largest city of the German western state of North Rhine-Westphalia (NRW) and the fourth-most populous city of Germany with 1.1 million inhabitants in the city proper and 3.6 millio ...

Germany Germany,, officially the Federal Republic of Germany, is a country in Central Europe. It is the second most populous country in Europe after Russia, and the most populous member state of the European Union. Germany is situated betwe ...

, the son of Roman law professor Franz Haymann (1874-1947) and Ruth Therese Hensel, daughter of mathematician

Kurt Hensel Kurt Wilhelm Sebastian Hensel (29 December 1861 – 1 June 1941) was a German mathematician born in Königsberg. Life and career Hensel was born in Königsberg, East Prussia (today Kaliningrad, Russia), the son of Julia (née von Adelson) and lan ...

. He was a great-grandson of acclaimed composer Fanny Mendelssohn. Because of his Jewish heritage, he left Germany, then under Nazi rule, alone by train in 1938. He continued his schooling at

Gordonstoun School Gordonstoun School is a co-educational independent school for boarding and day pupils in Moray, Scotland. It is named after the estate owned by Sir Robert Gordon in the 17th century; the school now uses this estate as its campus. It is located ...

, and later at St John's College, Cambridge under

John Edensor Littlewood John Edensor Littlewood (9 June 1885 – 6 September 1977) was a British mathematician. He worked on topics relating to analysis, number theory, and differential equations, and had lengthy collaborations with G. H. Hardy, Srinivasa Ramanu ...

and his doctoral advisor

Mary Cartwright Dame Mary Lucy Cartwright, (17 December 1900 – 3 April 1998) was a British mathematician. She was one of the pioneers of what would later become known as chaos theory. Along with J. E. Littlewood, Cartwright saw many solutions to a problem ...

. He taught at

King's College, Newcastle Newcastle University (legally the University of Newcastle upon Tyne) is a UK public research university based in Newcastle upon Tyne, North East England. It has overseas campuses in Singapore and Malaysia. The university is a red brick unive ...

, and the

University of Exeter , mottoeng = "We Follow the Light" , established = 1838 - St Luke's College1855 - Exeter School of Art1863 - Exeter School of Science 1955 - University of Exeter (received royal charter) , type = Public , ...

. In 1947, he married Margaret Riley Crann: together, they founded the

British Mathematical Olympiad The British Mathematical Olympiad (BMO) forms part of the selection process for the UK International Mathematical Olympiad team and for other international maths competitions, including the European Girls' Mathematical Olympiad, the Romanian Mas ...

. He is known for his asymptotic results in

Bieberbach conjecture In complex analysis, de Branges's theorem, or the Bieberbach conjecture, is a theorem that gives a necessary condition on a holomorphic function in order for it to map the open unit disk of the complex plane injectively to the complex plane. It ...

in 1955, and for Hayman's alternatives in

Nevanlinna Theory In the mathematical field of complex analysis, Nevanlinna theory is part of the theory of meromorphic functions. It was devised in 1925, by Rolf Nevanlinna. Hermann Weyl called it "one of the few great mathematical events of (the twentieth) century ...

. His work with Wolfgang Fuchs gave a solution to an inverse problem of the Nevanlinna theory for entire functions, predating David Drasin's 1976 work.

Honours and awards

Hayman was elected to the

Royal Society The Royal Society, formally The Royal Society of London for Improving Natural Knowledge, is a learned society and the United Kingdom's national academy of sciences. The society fulfils a number of roles: promoting science and its benefits, re ...

in 1956 and of the

Finnish Academy of Science and Letters The Finnish Academy of Science and Letters (Finnish ''Suomalainen Tiedeakatemia''; Latin ''Academia Scientiarum Fennica'') is a Finnish learned society. It was founded in 1908 and is thus the second oldest academy in Finland. The oldest is the Fi ...

in 1978: he was elected "Foreign member" of the Accademia dei Lincei on 16 December 1985. In 1992 he received an honorary doctorate from the Faculty of Mathematics and Science at

Uppsala University Uppsala University ( sv, Uppsala universitet) is a public research university in Uppsala, Sweden. Founded in 1477, it is the oldest university in Sweden and the Nordic countries still in operation. The university rose to significance during ...

, Sweden In 1995 he was awarded the

De Morgan Medal The De Morgan Medal is a prize for outstanding contribution to mathematics, awarded by the London Mathematical Society. The Society's most prestigious award, it is given in memory of Augustus De Morgan, who was the first President of the society ...

by the London Mathematical Society. In 2008, an issue of the Journal ''Computational Methods and Function Theory'' was dedicated to him on the occasion of his 80th birthday.

Selected publications

Papers

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Books

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Notes

References

Biographical references

*. The "''Yearbook''" of the renowned Italian scientific institution, including an historical sketch of its history, the list of all past and present members as well as a wealth of information about its academic and scientific activities. *. *.

General references

*. The review of the autobiographical book of Hayman. * (online ).

External links

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Obituary
at the London Mathematical Society {{DEFAULTSORT:Hayman, Walter 1926 births 2020 deaths 20th-century British mathematicians 21st-century British mathematicians People educated at Gordonstoun Alumni of St John's College, Cambridge Fellows of the Royal Society German expatriates in the United Kingdom British people of German-Jewish descent Complex analysts Mathematical analysts Mathematics education in the United Kingdom Deans of the Royal College of Science De Morgan Medallists