Dan Barbilian

Ion Barbu (Romanian pronunciation: [iˈon ˈbarbu], pen name of Dan Barbilian; 18 March 1895 –11 August 1961) was a Romanian mathematician and poet.

Born in Câmpulung-Muscel, Argeş County, he was the son of Constantin Barbilian and Smaranda, born Şoiculescu. He attended the Ion Brătianu High School in Piteşti and the Gheorghe Lazăr High School in Bucharest. During that time, he discovered that he had a talent for mathematics, and started publishing in Gazeta Matematică, one of the most prestigious math publications of that time; it was also then that he discovered his passion for poetry. Ion Barbu was known as "one of the greatest Romanian poets of the twentieth century and perhaps the greatest of all" according to Romanian literary critic Alexandru Ciorănescu. As a poet, he is best known for his volume Joc secund ("Mirrored Play").

He was a student at the University of Bucharest when World War I caused his studies to be interrupted by military service. He completed his degree in 1921. He then went to Göttingen University to study number theory with Edmund Landau for two years. Returning to Bucharest, he studied with Gheorghe Țițeica, completing his thesis in 1929

In 1934, Barbilian published his article describing metrization of a region K, the interior of a simple closed curve J. Let xy denote the Euclidean distance from x to y. Barbilian’s function for the distance from a to b in K is

...
Wikipedia