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# Saharon Shelah

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, U.S..

Biography

Shelah was born in Jerusalem on July 3, 1945. He is the son of the Israeli poet and political activist Yonatan Ratosh.[1] He received his Ph.D. in 1969 from the Hebrew University.[2]

Shelah is married to Yael,[1] and has three children.[3]

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. In 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 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;[4]

* The Israel Prize, for mathematics, in 1998;[5]

* The Bolyai Prize in 2000;[6]

* The Wolf Prize in Mathematics in 2001.[7]

References

1. ^ a b (Hebrew) Shelah, Saharon (2001-04-05). "זיכרונותיו של בן (Memoirs of a Son)". Haaretz. http://www.haaretz.co.il/hasite/pages/ShArt.jhtml?itemNo=24880. "כשעמדתי להציג לפני חברתי יעל (עתה רעייתי) את בני משפחתי…הפרופ' שהרן שלח מן האוניברסיטה העברית בירושלים, בנו של יונתן רטוש…"

2. ^ Saharon Shelah at the Mathematics Genealogy Project

3. ^ (Hungarian) Réka, Szász (March 2001). "Harc a matematikával és a titkárnőkkel". Magyar Tudományos. http://www.matud.iif.hu/01mar/shelah.html. "Hungarian: A gyerekei mivel foglalkoznak? A nagyobbik fiam zeneelméletet tanul, a lányom történelmet, a kisebbik fiam pedig biológiát. What are your children doing? My oldest son is learning the theory of music, my daughter history, my youngest son biology."

4. ^ "Erdos Prize Website". IMU.org.il. http://imu.org.il/ErdosPrize/erdos_prize.html#english.

5. ^ "Israel Prize Official Site - Recipients in 1998 (in Hebrew)". CMS.education.gov.il. 6. ^ "Laudation of Shelah on the occasion of winning the Bolyai Prize (in Hungarian)". Renyi.hu. http://www.renyi.hu/~csirmaz/shelah/sh.pdf.

7. ^ "The Wolf Foundation Prize in Mathematics". Wolf Foundation. 2008. http://www.wolffund.org.il/cat.asp?id=23&cat_title=Mathematics. Retrieved 2008-04-08.

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

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