Haim Hanani ( as Chaim Chojnacki– 8 April 1991) was a Polish-born Israeli mathematician, known for his contributions to

combinatorial design theory Combinatorial design theory is the part of combinatorial mathematics that deals with the existence, construction and properties of systems of finite sets whose arrangements satisfy generalized concepts of ''balance'' and/or ''symmetry''. These c ...

, in particular for the theory of pairwise balanced designs and for the proof of an existence theorem for Steiner quadruple systems. He is also known for the

Hanani–Tutte theorem In topological graph theory, the Hanani–Tutte theorem is a result on the parity of edge crossings in a graph drawing. It states that every drawing in the plane of a non-planar graph contains a pair of independent edges (not both sharing an end ...

on odd crossings in non-planar graphs.

Life

Hanani (Chojnacki) was born in

Poland Poland, officially the Republic of Poland, is a country in Central Europe. It is divided into 16 administrative provinces called voivodeships, covering an area of . Poland has a population of over 38 million and is the fifth-most populous ...

, studied in Vienna and Warsaw, and graduated with an M.A. from the

University of Warsaw The University of Warsaw ( pl, Uniwersytet Warszawski, la, Universitas Varsoviensis) is a public university in Warsaw, Poland. Established in 1816, it is the largest institution of higher learning in the country offering 37 different fields of ...

in 1934. He emigrated to the

British Mandate of Palestine British Mandate of Palestine or Palestine Mandate most often refers to: * Mandate for Palestine: a League of Nations mandate under which the British controlled an area which included Mandatory Palestine and the Emirate of Transjordan. * Mandatory P ...

, later to become

Israel Israel (; he, יִשְׂרָאֵל, ; ar, إِسْرَائِيل, ), officially the State of Israel ( he, מְדִינַת יִשְׂרָאֵל, label=none, translit=Medīnat Yīsrāʾēl; ), is a country in Western Asia. It is situated ...

, in 1935 and in 1938 received the first Ph.D. in Mathematics from the

Hebrew University of Jerusalem The Hebrew University of Jerusalem (HUJI; he, הַאוּנִיבֶרְסִיטָה הַעִבְרִית בִּירוּשָׁלַיִם) is a public research university based in Jerusalem, Israel. Co-founded by Albert Einstein and Dr. Chaim Weiz ...

. In 1955 he was appointed to the faculty at Technion Institute of Technology and from 1969 to 1973 he served as the rector of

Ben-Gurion University Ben-Gurion University of the Negev (BGU) ( he, אוניברסיטת בן-גוריון בנגב, ''Universitat Ben-Guriyon baNegev'') is a public research university in Beersheba, Israel. Ben-Gurion University of the Negev has five campuses: the ...

Beersheba Beersheba or Beer Sheva, officially Be'er-Sheva ( he, בְּאֵר שֶׁבַע, ''Bəʾēr Ševaʿ'', ; ar, بئر السبع, Biʾr as-Sabʿ, Well of the Oath or Well of the Seven), is the largest city in the Negev desert of southern Israel. ...

. In 1980 he was awarded the title of Professor Emeritus at that institution. His early research led to the proof of the theorem devised by Richard M. Wilson on pairwise balance designs. He wrote scholarly papers with

Andries Brouwer Andries Evert Brouwer (born 1951) is a Dutch mathematician and computer programmer, Professor Emeritus at Eindhoven University of Technology (TU/e). He is known as the creator of the greatly expanded 1984 to 1985 versions of the roguelike compute ...

Paul Erdős Paul Erdős ( hu, Erdős Pál ; 26 March 1913 – 20 September 1996) was a Hungarian mathematician. He was one of the most prolific mathematicians and producers of mathematical conjectures of the 20th century. pursued and proposed problems in ...

Alexander Schrijver Alexander (Lex) Schrijver (born 4 May 1948 in Amsterdam) is a Dutch mathematician and computer scientist, a professor of discrete mathematics and optimization at the University of Amsterdam and a fellow at the Centrum Wiskunde & Informatica in Ams ...

, and Richard M. Wilson, among others. His papers were published in journals such as ''

Discrete Mathematics Discrete mathematics is the study of mathematical structures that can be considered "discrete" (in a way analogous to discrete variables, having a bijection with the set of natural numbers) rather than "continuous" (analogously to continuous f ...

'', the ''

Journal of Combinatorial Theory The ''Journal of Combinatorial Theory'', Series A and Series B, are mathematical journals specializing in combinatorics and related areas. They are published by Elsevier. ''Series A'' is concerned primarily with structures, designs, and applicat ...

'', the ''

European Journal of Combinatorics European, or Europeans, or Europeneans, may refer to: In general * ''European'', an adjective referring to something of, from, or related to Europe ** Ethnic groups in Europe ** Demographics of Europe ** European cuisine, the cuisines of Europe ...

'', and the ''

American Mathematical Monthly ''The American Mathematical Monthly'' is a mathematical journal founded by Benjamin Finkel in 1894. It is published ten times each year by Taylor & Francis for the Mathematical Association of America. The ''American Mathematical Monthly'' is an e ...

''.

Academic papers

* * * * * * * * * * * * * * * * * *

References

{{DEFAULTSORT:Hanani, Haim 20th-century Polish mathematicians Polish emigrants to Mandatory Palestine 20th-century Israeli Jews 20th-century Israeli mathematicians 1912 births 1991 deaths