**Johannes Haantjes** was a Dutch mathematician who worked in differential geometry.

- After graduating from the High School in Leiden in 1927, Haantjes entered the University of Leiden where his chosen major subjects were mathematic and physics.
- Haantjes was also taught by Jan Arnoldus Schouten who was the professor of mathematics at Delft University but taught a course on differential geometry at Leiden as a guest lecturer.
- Another of Haantjes' lecturers was Johannes Droste (1886-1963).
- Haantjes continued his studies at the University of Leiden, undertaking research for his doctorate advised by van der Woude.
- Although Jan Schouten was not on the faculty of the University of Leiden, he did advise Haantjes in an unofficial capacity.
- On 19 May 1933 Haantjes was awarded a Ph.D. for his 102-page thesis Het beweeglijk assenstelsel in de affiene ruimte Ⓣ(The moving coordinate system in the affine space).
- A few months after Haantjes' thesis was accepted, his first paper, a joint publication with his thesis advisor van der Woude appeared.
- By the time this paper was published, Haantjes was already working as an assistant to Jan Schouten at Delft University.
- Schouten and Haantjes published two joint papers in 1934, namely Generelle Feldtheorie.
- In 1936 Haantjes and Jan Schouten were co-authors of the article On the theory of the geometric object which was published in the Proceedings of the Edinburgh Mathematical Society.
- Marie Antoinette Haantjes died in 2001.
- Haantjes gave his inaugural lecture Over enige grondbegrippen uit de meetkunde Ⓣ(On some basic concepts of geometry) in Leiden on 28 May 1948.
- Haantjes published over 50 papers in his short career and we will now look at the titles and give a short extract from a review, of a few of these.
- Haantjes also wrote the book Inleiding tot de Differentiaalmeetkunde Ⓣ(Introduction to differential geometry) (1954).
- Today Haantjes is remembered by those working in metric geometry for the Haantjes-Finsler curve.
- The Haantjes-Finsler curve is a metric notion of curvature suggested by Paul Finsler and developed by Haantjes in his paper Distance geometry.
- Haantjes was a dedicated Christian who had many social interests.
- H D Kloosterman was chair of this committee with Haantjes as its secretary.
- This shows the strong international reputation that Haantjes had acquired.

Born 18 September 1909, Itens, Friesland, Netherlands. Died 8 February 1956, Leiden, Netherlands.

View full biography at MacTutor

Origin Netherlands

**O’Connor, John J; Robertson, Edmund F**: MacTutor History of Mathematics Archive