West was elected to the Royal Society in 2006; his citation read
Professor West is distinguished for the development of the theory of supersymmetry and its application to the construction of unified theories of all the fundamental particle interactions. His results have become cornerstones of the modern theory of superstrings and associated branes to which he continues to contribute actively.[3]
Peter West is one of the pioneers of supersymmetry and its application to string theory. He discovered many of the quantum properties of supersymmetric theories in four dimensions including an early version of the supersymmetry nonrenormalization theorems[10] and the superconformal invariance of large classes of supersymmetric quantum field theories, including the maximally supersymmetric N = 4 supersymmetric Yang–Mills theory,[11] which has 16 supersymmetries, theories with 8 supersymmetries[12] and 4 supersymmetries.[13][14][15] The non-renormalization theorem plays a key role in determining how supersymmetry might be realised in nature and the above were the first discovered non-trivial conformal quantum field theories in four dimensions.
West constructed the two maximal supergravity theories that exist in ten dimensions; the IIA theory [4] and, with Paul Howe and John Henry Schwarz, the IIB theory.[16][5] These theories are the low energy effective actions, including non-perturbative effects, of the corresponding string theories and as a result they are one of the cornerstones in our understanding of string theory. Kellogg Stelle and West,[17] and at the same time Sergio Ferrara and Peter van Nieuwenhuizen,[18] found the supergravity theory in four dimensions which possesses an algebra with four supersymmetries which existed without the use of the equations of motion that is, they found the auxiliary fields that extended the first discovered supergravity theory.[19][20] Using this off-shell formulation West and Stelle,[21][22] together with the complementary work of Ferrara and van Nieuwenhuizen,[23] introduced a tensor calculus for supergravity and this led to the construction of the most general supersymmetric theory in four dimensions, which has played a crucial role in the construction of realistic supersymmetric models.
West, together with Ali Chamseddine, formulated both ordinary gravity and supergravity as a Yang–Mills theory[24] and so provided the first algebraic proof of the supersymmetric invariance of supergravity theories. The gauging approach of Chamseddine and West was different to the earlier ideas of gauging to find gravity that took the Poincaré transformations on Minkowski spacetime and made them local, that is, they took the translations to depend on spacetime. The gauging method of Chamseddine and West has been used to construct conformal supergravity theories and plays a key role in the formulation of higher spin theories.
André Neveu and West pioneered the development of gauge covariant string theory; including the free term [25] and the general features of the interacting theory.[26][27][28] A complete formulation of gauge covariant open string theory was found by Edward Witten.[29]
More recently West has proposed that M-theory, the underlying theory of strings and branes, should have a very large Kac–Moody algebra, called E11, as a symmetry.[30][31] He has shown that this theory contains all the maximal supergravity theories.[32]
Books
Introduction to Supersymmetry and Supergravity, P. West (World Scientific Publishing, 1986) (an extended and revised second edition was published in 1990 by World Scientific Publishing, ISBN981-02-0098-6)
Introduction to Strings and Branes, P. West (Cambridge University Press, 2012)