Gregory J. Chaitin (born 1947) is an American contemporary mathematician and computer scientist.

Chaitin, beginning in the late 1960s, made important contributions to algorithmic information theory, in particular a new incompleteness theorem similar in spirit to Gödel's incompleteness theorem. In 1995 he was given the degree of doctor of science honoris causa by the University of Maine. In 2002 he was given the title of honorary professor by the University of Buenos Aires in Argentina, where his parents were born and where Chaitin spent part of his youth. He is also a visiting professor at the Computer Science Department of the University of Auckland.

Chaitin has defined Chaitin's constant Ω, a real number whose digits are equidistributed and which expresses the probability that a random program will halt. Ω has numerous remarkable mathematical properties, including the fact that it is definable but not computable.

Chaitin's work on algorithmic information theory paralleled the earlier work of Kolmogorov in many respects.

Books

• Algorithmic Information Theory, (Cambridge University Press, 1987),
• Information, Randomness & Incompleteness, (World Scientific, 1987),
• Information-Theoretic Incompleteness, (World Scientific, 1992),
• The Limits of Mathematics, (Springer-Verlag 1998),
• The Unknowable, (Springer-Verlag 1999),
• Exploring Randomness, (Springer-Verlag 2001),
• Conversations with a Mathematician, (Springer-Verlag 2002),
• From Philosophy to Program Size, (Tallinn Cybernetics Institute 2003),
• Meta Math!, (Pantheon 2005).

External links

• G J Chaitin Home Page
• List of publications of G J Chaitin