Frhlich, Albrecht

Frhlich was born on 22 May 1916 in Munich, Germany to Julius and Frieda Frhlich. The family were Jewish and Julius Frhlich was a cattle merchant. Albrecht was the youngest of three children. The eldest, his sister Betti, settled in Palestine in the 1920s and his elder brother Herbert was to become a distinguished physicist. After elementary school Frhlich went to the Wittelsbacher Gymnasium but with the rise to power of the Nazis Frhlich and his parents left Germany for France in 1933, and the following year moved to Palestine to join Betti (Herbert had gone to the University of Leningrad in 1934, then to the University of Bristol in 1935). In Palestine Frhlich worked as a plumber and then as an electrician in a railway workshop.

Frhlich had ended his formal education at the age of seventeen when he fled Germany. However, in 1945 Herbert, now Reader in Physics at the University of Bristol, arranged for his younger brother to join him at Bristol. Frhlich was accepted as a student and began his studies in mathematics in December 1945. He graduated with First Class Honours in 1948 and began post-graduate research under H.A. Heilbronn. Frhlich completed his doctoral thesis in October 1950 (Ph.D. awarded 1951). While an undergraduate at Bristol Frhlich met a medical student, Ruth Brooks, whom he married in 1950. She became a doctor in general practice, while also accompanying her husband on many of his visits abroad and bringing up their children.

Frhlich was Assistant Lecturer in Mathematics at the University of Leicester 1950-1952 and Lecturer in Pure Mathematics at the University College of North Staffordshire 1952-1955. In 1955 he was appointed Reader in Mathematics at King's College London. Subsequently he became Professor of Mathematics at King's (1962), Head of Department (1969) and, on retirement, Emeritus Professor (1981). He remained active in post-retirement research and appointments included Fellowship of Robinson College, Cambridge in 1982 (Emeritus Fellow 1984) and a Senior Research Fellowship at Imperial College London in 1982. During his career Frhlich held numerous Visiting Professorships, enjoying a particularly close relationship with the University of Bordeaux (Visiting Professor 1975 and 1984). He also made many conference visits to the USA, Germany and France.

Frhlich's contributions to algebraic number theory and to mathematics more widely were acknowledged in the citation for the de Morgan Medal of the London Mathematical Society, awarded in 1992.

'His research is characterised by a prodigious flow of highly original ideas, which still shows no sign of stopping. His work includes such topics as class two nilpotent Galois groups, class groups of abelian fields, genus theory, quadratic forms and orthogonal representations, and local Langlands theory. However, without any doubt his most important achievement is the creation of that body of knowledge now known as arithmetic Galois module theory: this seeks to exploit and develop the mysterious and wonderful relationship between certain analytic invariants, called Artin root numbers, and the purely arithmetic problem of determining the structure of the ring of integers of a Galois extension of number fields over the integral group ring of the Galois group. Although there were a few previous results due to Hilbert and Noether, the subject really took off with Frhlich's seminal work on tame Hs-extensions. Building on this, he then proceeded to develop a general theory and, in the process, produced a whole fund of new ideas and techniques. Through his work and direction this subject has helped keep British number theory at the forefront of mainstream research.

Frhlich has greatly influenced the development of algebraic number theory in many ways; he has published seven books, written over a hundred papers and, jointly with J.W.S. Cassels, he organised the renowned Brighton conference, which did so much to make class field theory more widely accessible.

Special mention should be made of the help and encouragement that he has consistently given to young mathematicians: in addition to his many own research students, there have been many French and German students to whom he has provided considerable help. His enthusiasm and love for mathematics are a source of inspiration to all who have worked with him'.

In addition to the de Morgan Medal of the London Mathematical Society, he had also received the Society's Senior Berwick Prize in 1976. Frhlich received honorary doctorates from the universities of Bordeaux (1986) and Bristol (1998) and the Alexander von Humboldt Foundation Humboldt Research Award for the Scientific Cooperation between Great Britain and Germany in 1992. He was elected a FRS in 1976. He died 8 November 2001.

For a full account of Frhlich's life and works see 'Albrecht Frhlich (22 May 1916 - 8 November 2001)' by B.J. Birch and M.J. Taylor, Biographical Memoirs of Fellows of the Royal Society vol. 51 (2005), 149-168.