János Kollár

János Kollár (born June 7, 1956) is a Hungarian mathematician, specializing in algebraic geometry.
Professional career
Kollár began his studies at the Eötvös University in Budapest and later received his PhD at Brandeis University in 1984 under the direction of Teruhisa Matsusaka with a thesis on canonical threefolds. He was Junior Fellow at Harvard from 1984 to 1987 and Professor at the University of Utah from 1987 until 1999. Currently, he is professor at Princeton University.
Contributions
Kollár is known for his contributions to the minimal model program for threefolds and hence the compactification of moduli of surfaces, for pioneering the notion of rational connectedness (i.e. extending the theory of rationally connected varieties for varieties over the complex field to varieties over local fields), and finding counterexamples to a conjecture of John Nash. (In 1952 Nash conjectured a converse to a famous theorem he...