András Sárközy is a Hungarian

Hungary

Hungary , officially the Republic of Hungary , is a landlocked country in Central Europe. It is situated in the Carpathian Basin and is bordered by Slovakia to the north, Ukraine and Romania to the east, Serbia and Croatia to the south, Slovenia to the southwest and Austria to the west. The...

 mathematician

Mathematician

A mathematician is a person whose primary area of study is the field of mathematics. Mathematicians are concerned with quantity, structure, space, and change....

, working in analytic

Analytic number theory

In mathematics, analytic number theory is a branch of number theory that uses methods from mathematical analysis to solve problems about the integers. It is often said to have begun with Dirichlet's introduction of Dirichlet L-functions to give the first proof of Dirichlet's theorem on arithmetic...

 and combinatorial number theory, although his first works were in the fields of geometry

Geometry

Geometry arose as the field of knowledge dealing with spatial relationships. Geometry was one of the two fields of pre-modern mathematics, the other being the study of numbers ....

 and classical analysis. He has the largest number of papers co-authored with Paul Erdős

Paul Erdos

Paul Erdős was a Hungarian mathematician. Erdős published more papers than any other mathematician in history, working with hundreds of collaborators. He worked on problems in combinatorics, graph theory, number theory, classical analysis, approximation theory, set theory, and probability theory...

. He proved that every sequence of natural numbers with positive upper density

Natural density

In number theory, asymptotic density is one of the possibilities to measure how large a subset of the set of natural numbers is....

 contains two members whose difference is a full square. He was elected a corresponding member (1998), and a full member (2004) of the Hungarian Academy of Sciences

Hungarian Academy of Sciences

The Hungarian Academy of Sciences is the most important and prestigious learned society of Hungary. Its seat is at the bank of the Danube in Budapest.-History:...

. He received the Széchenyi Prize

Széchenyi Prize

The Széchenyi Prize , named after István Széchenyi, is a prize given in Hungary by the state, replacing the former State Prize in 1990 in recognition of those who have made an outstanding contribution to academic life in Hungary.-External links:*...

(2010).