Jens Feder  Gottfried Jens Feder (31 January 1939 – 15 February 2019) was a Norwegian physicist. He took the dr.philos. degree in 1970, and became a professor of physics at the University of Oslo, only 35 years old. His research fields have been broad and varied; a book on fractals was translated into several languages, among others Japanese and Russian. He has cooperated closely with physicist Torstein Jøssang, but also with colleagues worldwide. He was a fellow of the Norwegian Academy of Science and Letters. He resided at Slemdal.