Moti Gitik () is a mathematician, working in
set theory
Set theory is the branch of mathematical logic that studies sets, which can be informally described as collections of objects. Although objects of any kind can be collected into a set, set theory, as a branch of mathematics, is mostly concer ...
, who is professor at the
Tel-Aviv University
Tel Aviv University (TAU) ( he, אוּנִיבֶרְסִיטַת תֵּל אָבִיב, ''Universitat Tel Aviv'') is a public research university in Tel Aviv, Israel. With over 30,000 students, it is the largest university in the country. Loc ...
. He was an
invited speaker at the 2002
International Congresses of Mathematicians
The International Congress of Mathematicians (ICM) is the largest conference for the topic of mathematics. It meets once every four years, hosted by the International Mathematical Union (IMU).
The Fields Medals, the Nevanlinna Prize (to be rename ...
, and became a fellow of the
American Mathematical Society
The American Mathematical Society (AMS) is an association of professional mathematicians dedicated to the interests of mathematical research and scholarship, and serves the national and international community through its publications, meetings ...
in 2012.
List of Fellows of the American Mathematical Society
retrieved 2013-01-19.
Research
Gitik proved the consistency
In classical deductive logic, a consistent theory is one that does not lead to a logical contradiction. The lack of contradiction can be defined in either semantic or syntactic terms. The semantic definition states that a theory is consistent ...
of "all uncountable cardinals are singular
Singular may refer to:
* Singular, the grammatical number that denotes a unit quantity, as opposed to the plural and other forms
* Singular homology
* SINGULAR, an open source Computer Algebra System (CAS)
* Singular or sounder, a group of boar ...
" (a strong negation of the axiom of choice
In mathematics, the axiom of choice, or AC, is an axiom of set theory equivalent to the statement that ''a Cartesian product of a collection of non-empty sets is non-empty''. Informally put, the axiom of choice says that given any collection ...
) from the consistency of "there is a proper class of strongly compact cardinal In set theory, a branch of mathematics, a strongly compact cardinal is a certain kind of large cardinal.
A cardinal κ is strongly compact if and only if every κ-complete filter can be extended to a κ-complete ultrafilter.
Strongly compact card ...
s". He further proved the equiconsistency of the following statements:
* There is a cardinal ''κ'' with Mitchell order ''κ''++.
* There is a measurable cardinal
In mathematics, a measurable cardinal is a certain kind of large cardinal number. In order to define the concept, one introduces a two-valued measure on a cardinal , or more generally on any set. For a cardinal , it can be described as a subdivis ...
''κ'' with 2''κ'' > ''κ''+.
* There is a strong limit singular cardinal ''λ'' with 2''λ'' > ''λ''+.
* The GCH holds below ℵω, and 2ℵω=ℵω+2.
Gitik discovered several methods for building models of ZFC with complicated Cardinal Arithmetic structure. His main results deal with consistency and equi-consistency of non-trivial patterns of the Power Function over singular cardinals.
Selected publications
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See also
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References
{{DEFAULTSORT:Gitik, Moti
Living people
Tel Aviv University faculty
Fellows of the American Mathematical Society
20th-century Israeli mathematicians
21st-century Israeli mathematicians
Set theorists
Year of birth missing (living people)