Biography of J.W.S. Cassels

J. W. S. Cassels (known to his friends by the Gaelic form "Ian" of his first name) was born of mixed English-Scottish parentage on 11 July 1922 in the picturesque cathedral city of Durham. With a first degree from Edinburgh, he commenced research in Cambridge in 1946 under L. J. Mordell, who had just succeeded G. H. Hardy in the Sadleirian Chair of Pure Mathematics. He obtained his doctorate and was elected a Fellow of Trinity College in 1949. After a year in Manchester, he returned to Cambridge and in 1967 became Sadleirian Professor. He was Head of the Department of Pure Mathematics and Mathematical Statistics from 1969 until he retired in 1984.

Cassels has contributed to several areas of number theory and written a number of other expository books:
- An introduction to diophantine approximations
- Rational quadratic forms
- Economics for mathematicians
- Local fields
- Lectures on elliptic curves
- Prolegomena to a middlebrow arithmetic of curves of genus 2 (with E. V. Flynn).

Prologue.- I. Lattices.- 1. Introduction.- 2. Bases and sublattices.- 3. Lattices under linear transformation.- 4. Forms and lattices.- 5. The polar lattice.- II. Reduction.- 1. Introduction.- 2. The basic process.- 3. Definite quadratic forms.- 4. Indefinite quadratic forms.- 5. Binary cubic forms.- 6. Other forms.- III. Theorems of BLICHFELDT and MINKOWSKI.- 1. Introduction.- 2. BLICHFELDT'S and MINKOWSKI'S theorems.- 3. Generalisations to non-negative functions.- 4. Characterisation of lattices.- 5. Lattice constants.- 6. A method of MORDELL.- 7. Representation of integers by quadratic forms.- IV. Distance functions.- 1. Introduction.- 2. General distance-functions.- 3. Convex sets.- 4. Distance functions and lattices.- V. MAHLER'S compactness theorem.- 1. Introduction.- 2. Linear transformations.- 3. Convergence of lattices.- 4. Compactness for lattices.- 5. Critical lattices.- 6. Bounded star-bodies.- 7. Reducibility.- 8. Convex bodies.- 9. Spheres.- 10. Applications to diophantine approximation.- VI. The theorem of MINKOWSKI-HLAWKA.- 1. Introduction.- 2. Sublattices of prime index.- 3. The Minkowski-Hlawka theorem.- 4. SCHMIDT'S theorems.- 5. A conjecture of ROGERS W.- 6. Unbounded star-bodies.- VII. The quotient space.- 1. Introduction.- 2. General properties.- 3. The sum theorem.- VIII. Successive minima.- 1. Introduction.- 2. Spheres.- 3. General distance-functions.- 4. Convex sets.- 5. Polar convex bodies.- IX. Packings.- 1. Introduction.- 2. Sets with V(L) = 2n?(L).- 3. VORONOI'S results.- 4. Preparatory lemmas.- 5. FEJES TÓTh'S theorem.- 6. Cylinders.- 7. Packing of spheres.- 8. The product of n linear forms.- X. Automorphs.- 1. Introduction.- 2. Special forms.- 3. A method of MORDELL.- 4. Existence of automorphs.- 5. Isolation theorems.- 6.Applications of isolation.- 7. An infinity of solutions.- 8. Local methods.- XI. Inhomogeneous problems.- 1. Introduction.- 2. Convex sets.- 3. Transference theorems for convex sets.- 4. The product of n linear forms.- References.