Saharon Shelah

Saharon Shelah
Saharon Shelah in his office in Rutgers University, September 6, 2005. Photo by Andrzej Rosłanowski.
Born	3 July 1945 (1945-07-03) Jerusalem, British Mandate for Palestine
Residence	Jerusalem, Israel
Nationality	Israel
Fields	Mathematics
Institutions	Hebrew University, Rutgers University
Alma mater	Hebrew University
Doctoral advisor	Michael O. Rabin
Doctoral students	Uri Abraham, Shai Ben-David, Rami Grossberg, Menachem Kojman, Mati Rubin
Known for	Mathematical logic, model theory, set theory
Notable awards	Wolf Prize, Israel Prize, Erdős Prize

Saharon Shelah (Hebrew: שהרן שלח‎) (1945 - ) is an Israeli mathematician. He is a professor of mathematics at the Hebrew University of Jerusalem and Rutgers University in New Jersey.

Biography

Shelah was born in Jerusalem on July 3, 1945. He is the son of the Israeli poet and political activist Yonatan Ratosh. He received his Ph.D. in 1969 from the Hebrew University.

Shelah is married to Yael, and has three children.

Academic career

Shelah is one of the most prolific contemporary mathematicians. As of 2009, he has published nearly 900 mathematical papers (together with over 200 co-authors). His main interests lie in mathematical logic, model theory in particular, and in axiomatic set theory.

In model theory, he developed the classification theory, which led him to a solution of Morley's problem. In set theory, he invented the notion of proper forcing, an important tool in iterated forcing arguments. With PCF theory, he showed that in spite of the undecidability of the most basic questions of cardinal arithmetic (such as the continuum hypothesis), there are still highly nontrivial ZFC theorems about cardinal exponentiation. Shelah constructed a Kurosh monster, an uncountable group for which every proper subgroup is countable. He showed that Whitehead's problem is independent of ZFC. He gave the first primitive recursive upper bound to van der Waerden's numbers V(C,N). He extended Arrow's impossibility theorem on voting systems.

Awards

• The first recipient of the Erdős Prize, in 1977;
• The Israel Prize, for mathematics, in 1998;
• The Bolyai Prize in 2000;
• The Wolf Prize in Mathematics in 2001.
• The EMET prize in 2011.

External links

• Archive of Shelah's mathematical papers, shelah.logic.at
• A survey of recent work on AECs, math.uic.edu

See also

• List of Israel Prize recipients