| Citation | Distinguished for his work in theoretical physics, and notably for the application of topological methods to problems in wave theory. Berry's work has illuminated especially the "semi-classical" areas where solutions in wave theory or quantum mechanics display features characteristic of ray theory or classical mechanics. This work has applications in atomic scattering and high voltage electron microscopy; and also in statistical mechanics, where Berry's concepts based on Wigner functions in phase space have shown the importance of non-integrable systems and are exposing their morphology. He has used Thom's theorem in differential topology predictively to understand the diffraction patters that clothe optical caustics, and thence has extended the theory of intensity fluctuations in random short waves, as in the twinkling of the stars, perceiving that they are dominated by caustics. He has shown how Thom's theorem can be applied to flow problems and (with J.F. Nye) has introduced into wave physics a new structural element, the wave dislocation. Recently he has solved problems of the evolution of a random fractal wavefront ("rough on all scales") and the distribution of modes in fractal resonators, as in natural objects like trees and lakes. All this work is characterised by exceptional originality, physical insight and elegance of execution. |