On some mathematical topics I found interesting.
Amalgamated products and HNN extensions
Amalgamated products and HNN extensions (IV): Markov properties
Amalgamated products and HNN extensions (III): Examples of non-hopfian groups
Amalgamated products and HNN extensions (II): Examples of non-finitely presented groups
Amalgamated products and HNN extensions (I): A theorem of B.H. Neumann
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
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