Presented by: 
Ben Burton, UQ
Tue 20 Aug, 3:00 pm - 4:00 pm
Room 442, Building 67

The crushing operation of Jaco and Rubinstein is a powerful technique in algorithmic topology: it enabled the first practical implementations of 3-sphere recognition and prime decomposition of orientable manifolds, and it plays a prominent role in the state-of-the-art algorithm for unknot recognition.

One of the greatest surprises of the crushing operation is that it works at all: the operation makes large and brutal changes to a triangulation, yet almost no topological information is lost.  In this talk we introduce the procedure and explain using a new and simple argument why it behaves so well.