Jakob Nielsen was a Danish mathematician and one of the pioneers of the combinatorial group theory. Nielsen-Schreier theorem, HNN-extensions, Nielsen–Thurston classification, Nielsen fixed point theorem, Nielsen invariant, Fenchel-Nielson coordinates? on Teichmüller space and Nielsen’s method of small cancellations were named after him.
Last revised on February 22, 2013 at 19:56:56. See the history of this page for a list of all contributions to it.