MORI SHIGEFUMI

born Feb. 23, 1951, Nagoya, Japan Japanese mathematician who was awarded the Fields Medal in 1990 for his work in algebraic geometry. Mori attended Kyoto University (B.A., 1973; M.A., 1975; Ph.D., 1978) and held an appointment there until 1980, when he went to Nagoya University. In 1990 he joined the faculty of the Research Institute for Mathematical Sciences at Kyoto. Mori was awarded the Fields Medal at the International Congress of Mathematicians in Kyoto in 1990. In 1979 Mori proved Hartshorne's conjecture, an unsolved problem in algebraic geometry. His most important work focused on the problem of classification of algebraic varietiessolution sets of systems of algebraic equations in some number of variablesin algebraic geometry. The problem of a full classification of algebraic varieties of dimension three was regarded as very difficult, and Mori developed new and powerful techniques to apply to the problem. These problems remain open for higher-dimensional algebraic varieties, although a number of specific results are known. Mori's publications include, with Herbert Clemens and Jnos Kollr, Higher Dimensional Complex Geometry (1988).