PLEMELJ, Josip
* 11. 12. 1873, Bled, Slovenia
† 22. 5. 1967, Ljubljana, Slovenia
mathematician
After graduating from the gymnasium in Ljubljana, P. studied mathematics, physics, and astronomy at the Faculty of Arts of the University of Vienna from 1894 onwards. He completed his studies in 1898 with a dissertation in the field of differential equations. Differential and integral equations, as well as the potential theory and the theory of functions, were P.‘s main fields of activity.
After a shorter stay in Berlin and Göttingen, where he educated himself further, he began performing the tasks of a private assistant professor at the University of Vienna in 1902. In 1906, he started working as an assistant at the Technical College of Vienna, while a year later he was invited by the University of Czẹrnowitz to the post of associate professor, and a year after that to that of full professor. In 1908, P. published an independent solution of the Riemann problem, for which he developed the so-called P. formulas, on which he founded the theory of singular integral equations. In 1911, he published a very important work on integral equations, Research in Potential Theory (Potentialtheoretische Untersuchungen), for which he received a prize from the Prince Jablonowski Scientific Society of Leipzig.
In the following decade, P. mostly devoted himself to teaching. During World War II, he was considered politically unreliable and was moved by force to Moravia in 1917, however, he was received by friends in Vienna. After the war, he returned to Bled and accepted a post at the newly established University of Ljubljana as a professor of mathematics. He remained at this post until he received his emeritus status in 1957. His colleagues chose him as first chancellor in 1919/20. P. was a member of the Serbian Academy of Sciences and Arts, and from 1938 onwards also a member of the Slovenian Academy of Sciences and Arts. In 1957, the Bavarian Academy of Sciences in Munich elected him its corresponding member.
