Saharon Shelah

Infobox_Scientist
name = Saharon Shelah

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image_width = 300px
caption = Professor Saharon Shelah in Jerusalem, March 2008
birth_date = Birth date and age|1945|7|3
birth_place = Jerusalem
residence = Jerusalem, Israel
nationality = ISR
ethnicity = Jewish
field = Mathematician
work_institution = Hebrew University, Rutgers University
alma_mater = Hebrew University
doctoral_advisor = Michael O. Rabin
doctoral_students = Mati Rubin, Uri Abraham, Menachem Kojman
known_for = Mathematical logic, Model theory, Set theory
prizes = Wolf Prize, Israel prize
footnotes = Son of Yonatan Ratosh

Saharon Shelah ( _he. שהרן שלח, born July 3, 1945 in Jerusalem) is an Israeli mathematician. He is a professor of mathematics at the Hebrew University of Jerusalem and also at Rutgers University in New Jersey, U.S.. Shelah's main interest lies in mathematical logic, in particular in model theory and set theory.

He received his Ph.D. in 1969 from the Hebrew University. [MathGenealogy |id=22575]

Shelah is one of the most prolific contemporary mathematicians. As of 2006, he had (together with over 200 co-authors) published nearly 900 mathematical papers. Among his most important results are:

* in model theory, the introduction and development of his "classification theory", which led him to a solution of Morley's problem
* in set theory,
** the invention of the notion of "proper forcing", an important tool in iterated forcing arguments
** PCF theory, which shows 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, after all.

Shelah also solved several outstanding questions from other fields, among them:
* He 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.

Shelah was awarded the Bolyai prize in 2000.

Shelah is the son of the Israeli poet and political activist Yonatan Ratosh.he icon cite web | url=http://www.haaretz.co.il/hasite/pages/ShArt.jhtml?itemNo=24880 | title= _he. זיכרונותיו של בן (Memoirs of a Son) | last=Shelah | first=Saharon | date=2001-04-05 | publisher=Haaretz | quote= _he. כשעמדתי להציג לפני חברתי יעל (עתה רעייתי) את בני משפחתי…הפרופ' שהרן שלח מן האוניברסיטה העברית בירושלים, בנו של יונתן רטוש…] He is married to Yael, and has three children. [hu icon cite web | url=http://www.matud.iif.hu/01mar/shelah.html | title= _hu. Harc a matematikával és a titkárnőkkel | last=Réka | first=Szász | year=2001 | month=March | work=Magyar Tudományos | quote=Lang-hu|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.]

References

External links

* [http://shelah.logic.at Archive of Shelah's mathematical papers]

Persondata
NAME= Shelah, Saharon
ALTERNATIVE NAMES=
SHORT DESCRIPTION= Israeli Mathematician
DATE OF BIRTH= July 3, 1945
PLACE OF BIRTH= Jerusalem, Israel
DATE OF DEATH=
PLACE OF DEATH=