In the 1950s,
homotopy theory was at an early stage of development, and unsolved problems abounded. Adams made a number of important theoretical advances in
algebraic topology, but his innovations were always motivated by specific problems. Influenced by the French school of
Henri Cartan and
Jean-Pierre Serre, he reformulated and strengthened their method of
killing homotopy groups in
spectral sequence terms, creating the basic tool of
stable homotopy theory now known as the
Adams spectral sequence. This begins with
Ext groups calculated over the ring of
cohomology operations, which is the
Steenrod algebra in the classical case. He used this
spectral sequence to attack the celebrated
Hopf invariant one problem, which he completely solved in a 1960 paper by making a deep analysis of
secondary cohomology operations. The
Adams–Novikov spectral sequence is an analogue of the Adams spectral sequence using an
extraordinary cohomology theory in place of classical cohomology: it is a computational tool of great potential scope. Adams was also a pioneer in the application of
K-theory. He invented the
Adams operations in K-theory, which are derived from the
exterior powers; they are now also widely used in purely algebraic contexts. Adams introduced them in a 1962 paper to solve the famous
vector fields on spheres problem. Subsequently he used them to investigate the
Adams conjecture, which is concerned (in one instance) with the image of the
J-homomorphism in the stable
homotopy groups of spheres. A later paper of Adams and
Michael F. Atiyah uses the Adams operations to give an extremely elegant and much faster version of the above-mentioned
Hopf invariant one result. In 1974 Adams became the first recipient of the
Senior Whitehead Prize, awarded by the
London Mathematical Society. He was a visiting scholar at the
Institute for Advanced Study in 1957–58. Adams had many talented students, and was highly influential in the development of
algebraic topology in Britain and worldwide. His
University of Chicago lectures were published in a 1996 series titled "Chicago Lectures in Mathematics Series", such as
Lectures on Exceptional Lie Groups and
Stable Homotopy and Generalised Homology . ==Recognition==