On some mathematical topics I found interesting.
Not all finitely-presented groups are fundamental groups of closed 3-manifolds
Positive curvature versus negative curvature
SO(3) is a simple group: a geometric proof
Hairy ball theorem without degree theory
When does a finite metric space embed isometrically into an euclidean space?
Polygons inscribed in curves
« Older posts
Exploring the works of Gilbert Baumslag
Gödel Lost Lettre and P=NP
Geometric Group Theory
Geometry and the Imagination
Here there be dragons
Image des Mathématiques
Low Dimensional Topology
Blog at WordPress.com.
Create a free website or blog at WordPress.com.
To find out more, including how to control cookies, see here: