Nicolaas de Bruijn Dutch mathematician Date of Birth: 09.07.1918 Country: Netherlands

1. Biography of Nicolas de Bruijn
2. Early Life and Education
3. Career and Contributions
4. Awards and Honors

Biography of Nicolas de Bruijn

Nicolas de Bruijn was a Dutch mathematician known for his research in graph theory, automated proof, and his textbook on asymptotic methods of analysis. Several constructions and concepts in these fields are named after him, including the de Bruijn cycle, the de Bruijn graph, and several well-known propositions in graph theory, combinatorics, computational geometry, and number theory.

Early Life and Education

Nicolas de Bruijn was born in 1918 in The Hague, Netherlands, into a large family of painters. From 1936 to 1941, he studied at Leiden University and worked as an assistant at the mathematics faculty of Delft University of Technology from 1939 to 1944. In 1943, he obtained his doctorate in mathematics from the University of Amsterdam, defending a dissertation on algebraic number theory under the guidance of Jurjen Koksma.

Career and Contributions

From 1944 to 1946, de Bruijn worked at the research laboratory of Philips Corporation. In 1946, he was appointed as a professor at the mathematics faculty of Delft University of Technology. During this period, he focused on combinatorics and incidence geometry, and his most significant result was the de Bruijn–Erdős theorem published jointly with Paul Erdős in 1948. This theorem provides a lower bound on the number of lines that can be drawn through a given set of points on a projective plane, analogous to Sylvester's theorem. Additionally, he and Erdős proved in 1951 that every k-chromatic graph contains a finite number of k-chromatic subgraphs, known as the de Bruijn–Erdős theorem.

In 1952, de Bruijn was invited to be a professor at the University of Amsterdam, where he worked until 1960. One of his notable works during this time was a lecture series on asymptotic methods of analysis, published as a book in 1958 and subsequently translated into Russian.

Starting from 1960, de Bruijn became a professor of mathematics at the Eindhoven University of Technology, a position he held until his retirement in 1984. In Eindhoven, he focused on analytical number theory, optimal control problems, and the mathematical description of quasicrystals, particularly Penrose tiling. In the late 1960s and early 1970s, his research shifted towards automated proof, and he developed the formal language Automath, which implemented the Curry-Howard correspondence, establishing a correspondence between formal proofs and computer programs. The typed λ-calculus, developed a few years later, was essentially a rediscovery of Automath.

In his later years, de Bruijn worked on modeling the human brain. He was elected a member of the Royal Netherlands Academy of Arts and Sciences in 1957 and served as an invited speaker at the International Congress of Mathematicians in Nice in 1970.

Awards and Honors

In 1981, Nicolas de Bruijn was awarded the Order of the Dutch Lion (Knight) and received the Snellius Medal in 1985.