Professor Toshiyuki Kobayashi has received the Medal with Purple Ribbon for his accomplishments in the field of mathematics.
Professor Takashi Tsuboi, Dean of the Graduate School of Mathematical Sciences
The Medal with Purple Ribbon is awarded to individuals with outstanding achievements in academics, arts and sports. Professor Toshiyuki Kobayashi has received it for his accomplishments in the field of mathematics.
Since the 1980s Professor Kobayashi has pioneered research on discontinuous groups in various geometries not restricted to Riemannian geometry, discovered a lot of interesting global geometric phenomena of locally homogeneous spaces of higher dimensions, and established the foundations of their theory by himself. His achievements have opened up new areas of research in the field containing geometry and Lie theory. His research ranges over algebra, geometry, and analysis where the key concept "symmetry" appears essentially, and has a great influence on the entire field of mathematics. In particular, "pioneering the theory of discontinuous groups for homogeneous spaces beyond Riemannian geometry", "creation of the theory of discretely decomposable restrictions in the theory of branching laws of infinite-dimensional representations", "global analysis arising from minimal representations", and "theory of visible action on complex manifolds towards a unified theory of multiplicity-free representations" are especially recognized internationally as remarkable achievements, bringing about essential breakthroughs in mathematics.
Despite the fact that these new theories are very unique and very original, they are rooted in the world of rich classical examples. In addition, his theories concern not a single field of mathematics, but the harmony of three major fields of pure mathematics: algebra, geometry, and analysis. The beauty and profundity of the theories attract mathematicians from all over the world, and he is often invited to give talks at important international conferences. He is indeed influential in modern mathematics.
― Office of Communication ―