Gerald Enoch Sacks (1933 – October 4, 2019) was a logician whose most important contributions were in recursion theory. Named after him is Sacks forcing, a forcing notion based on perfect sets[1] and the Sacks Density Theorem, which asserts that the partial order of the recursively enumerable Turing degrees is dense.[2] Sacks had a joint appointment as a professor at the Massachusetts Institute of Technology and at Harvard University starting in 1972 and became emeritus at M.I.T. in 2006 and at Harvard in 2012.[3][4][5]

Sacks was born in Brooklyn in 1933. He earned his Ph.D. in 1961 from Cornell University under the direction of J. Barkley Rosser, with his dissertation On Suborderings of Degrees of Recursive Insolvability. Among his notable students are Lenore Blum, Harvey Friedman, Sy Friedman, Leo Harrington, Richard Shore, Steve Simpson and Theodore Slaman.[6]

Selected publications

Degrees of unsolvability, Princeton University Press 1963, 1966[7]
Saturated Model Theory, Benjamin 1972; 2nd edition, World Scientific 2010[8]
Higher Recursion theory, Springer 1990[9]
Selected Logic Papers, World Scientific 1999[10]
Mathematical Logic in the 20th Century, World Scientific 2003


Halbeisen, Lorenz J. (2011), Combinatorial Set Theory: With a Gentle Introduction to Forcing, Springer Monographs in Mathematics, Springer, pp. 380–381, ISBN 9781447121732.
Soare, Robert I. (1987), Recursively Enumerable Sets and Degrees: A Study of Computable Functions and Computably Generated Sets, Perspectives in Mathematical Logic, Springer, p. 245, ISBN 9783540152996.
Short CV, retrieved 2015-06-26.
"Professor Gerald Sacks Retires from MIT" (PDF), Integral: News from the Mathematics Department at MIT, 1: 6, Autumn 2006.
Chi Tat Chong, Yue Yang, "An interview with Gerald E. Sacks", Recursion Theory: Computational Aspects of Definability, ISBN 3110275643, 2015, p. 275
Gerald Sacks at the Mathematics Genealogy Project
Review of Degrees of unsolvability by Kenneth Appel, MR0186554
Review of Saturated model theory by P. Stepanek, MR0398817
Review of Higher recursion theory by Dag Normann, MR1080970
Review of Selected logic papers by Dag Normann, MR1783306

Mathematics Encyclopedia



Hellenica World - Scientific Library

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