He obtained his PhD in 1983 from Florida State University with thesis Generalized Three-Manifolds with Zero-Dimensional Singular Set written under the direction of Robert Christopher Lacher.

[2] Since 1983 he has been the leader of the Slovenian Nonlinear Analysis, Topology and Geometry Group at the Institute of Mathematics, Physics and Mechanics in Ljubljana, and has directed numerous national and international research grants (with the United States, Japan, Russian Federation, China, France, Italy, Spain, Israel, United Kingdom, Poland, Hungary, Romania, Slovakia, and others).

He has published over 450 research papers and has given numerous invited talks at various international conferences and universities around the world.

[6][7] Later he extended his research to several other areas and is currently most actively investigating problems of partial differential equations.

[15] For his outstanding research he was awarded in 2014 the honorary doctorate by the University of Craiova,[16] in 2009 the Bogolyubov Memorial Medal by the Ukrainian Mathematical Congress in Kyiv and in 1997 the Prize of the Republic of Slovenia for Research (now called the Zois Prize).