Gregory Chaitin is an Argentine-American mathematician living in Rio de Janeiro, and a lifetime honorary professor of the University of Buenos Aires with an honorary doctorate in philosophy from the University of Córdoba,the oldest university in Argentina and one of the oldest in South America. He was formerly at the IBM Watson Research Center in New York, where he was part of a small team that developed the Power processor architecture and its associated software. On the theoretical side, Chaitin is best known for his discovery of the remarkable Ω number, a concrete example of irreducible complexity in pure mathematics, and which shows that mathematics is infinitely complex. For this he was awarded the Leibniz Medallion by Wolfram Research in 2007. He has also proposed modeling evolution as a random walk in software space (“metabiology”). Among his books are: Algorithmic Information Theory; Conversations with a Mathematician; Meta Math!; and Proving Darwin.
Festschriften: Cristian S. Calude, Randomness and Complexity, from Leibniz to Chaitin, World Scientific, Singapore, 2007; Gregory Chaitin, Thinking about Gödel and Turing: Essays on Complexity, 1970–2007, World Scientific, Singapore, 2007; Shyam Wuppuluri, Francisco Antonio Doria, Unravelling Complexity: The Life and Work of Gregory Chaitin, World Scientific, Singapore, 2020.