Sibe Mardeà ¡ià(June 20, 1927 - June 18, 2016) was a Croatian mathematician.
Sibe Mardeà ¡iàwas born in June 1927, in Bergedorf (near Hamburg, Germany), where his parents temporarily resided before moving to Chile. After that, they returned to Split, where he completed elementary school and high school. Soon after World War II he went to Zagreb to study mathematics. After graduation he took a job as an assistant at the Department of Mathematics of the University of Zagreb, where he stayed until his retirement in 1991. He was a full member of the Croatian Academy of Arts and Sciences, a corresponding member of the Slovenian Academy of Sciences and Arts and a Fellow of the American Mathematical Society.
Mardeà ¡iàwas a topologist who worked in all main branches of topology having published 148 research papers, 40 professional articles and 18 books. With Jack Segal, he developed an alternate approach to shape theory using inverse systems method of ANRs generalizing Borsuk's shape theory to include all compact Hausdorff spaces, independently of Tim Porter and Wà Âodzimierz Holsztyà Âski. Later he extended Holsztyà Âski's theory for compact Hausdorff spaces to all topological spaces. He introduced the first factorization theorem in dimension theory, the Mardeà ¡iàFactorization Theorem. With P. Papiàhe introduced the notion of feebly compact spaces.
He died on June 18, 2016, in Zagreb.