Ian C. Percival

Ian Colin Percival (born 1931) is a British theoretical physicist. He is the Emeritus Professor of the School of Physics and Astronomy at Queen Mary University, University of London. He is one among the pioneers of quantum chaos and he is well known for his suggestion in the 1970s about the existence of a different type of spectra of quantum-mechanical systems due to classical chaos. Numerical explorations performed by other researchers clearly confirmed this idea later. In 1987, with Franco Vivaldi, he used the algebraic number theory of quadratic number fields to count the periodic orbits in generalized Arnold-Sinai cat maps. Later on, he worked on the basics of quantum mechanics and the measurement process. Together with Walter Strunz, he suggested the properties of the quantum foam at the Planck scale (similar to the movement of particles due to Brownian motion) in the wave function of an atom-beam interference.