Alexander S. Kechris
Encyclopedia
Alexander Sotirios Kechris ' onMouseout='HidePop("67239")' href="/topics/Greece">Greece
) is a descriptive set theorist at Caltech. He has made major contributions to the theory of Borel equivalence relation
s.
Kechris earned his Ph.D.
in 1972 under the direction of Yiannis N. Moschovakis
, with a dissertation entitled Projective Ordinals
and Countable Analytic Sets
.
His Erdős number
is 2.
Greece
Greece , officially the Hellenic Republic , and historically Hellas or the Republic of Greece in English, is a country in southeastern Europe....
) is a descriptive set theorist at Caltech. He has made major contributions to the theory of Borel equivalence relation
Borel equivalence relation
In mathematics, a Borel equivalence relation on a Polish space X is an equivalence relation on X that is a Borel subset of X × X....
s.
Kechris earned his Ph.D.
Ph.D.
A Ph.D. is a Doctor of Philosophy, an academic degree.Ph.D. may also refer to:* Ph.D. , a 1980s British group*Piled Higher and Deeper, a web comic strip*PhD: Phantasy Degree, a Korean comic series* PhD Docbook renderer, an XML renderer...
in 1972 under the direction of Yiannis N. Moschovakis
Yiannis N. Moschovakis
Yiannis Nicholas Moschovakis is a set theorist, descriptive set theorist, and recursion theorist, at UCLA. For many years he has split his time between UCLA and University of Athens . His book Descriptive Set Theory is the primary reference for the subject...
, with a dissertation entitled Projective Ordinals
Ordinal number
In set theory, an ordinal number, or just ordinal, is the order type of a well-ordered set. They are usually identified with hereditarily transitive sets. Ordinals are an extension of the natural numbers different from integers and from cardinals...
and Countable Analytic Sets
Analytic set
In descriptive set theory, a subset of a Polish space X is an analytic set if it is a continuous image of a Polish space. These sets were first defined by and his student .- Definition :There are several equivalent definitions of analytic set...
.
His Erdős number
Erdos number
The Erdős number describes the "collaborative distance" between a person and mathematician Paul Erdős, as measured by authorship of mathematical papers.The same principle has been proposed for other eminent persons in other fields.- Overview :...
is 2.