Martin Scharlemann

Martin George Scharlemann is an American topologist who is a professor at University of California, Santa Barbara. He obtained his Ph.D. under the guidance of Robion Kirby in 1974.

A conference is his honor was held in 2009 at University of California, Davis. He is a Fellow of the American Mathematical Society, for his "contributions to low-dimensional topology and knot theory."

Abigail Thompson was a student of his. Together they solved the graph planarity problem: There is an algorithm to decide whether a finite graph in 3-space can be moved in 3-space into a plane.

He gave the first proof of the classical theorem that knots with unknotting number one are prime. He used hard combinatorial arguments for this. Simpler proofs are now known.