"What is ... a van Kampen obstruction cocycle" -- Isaac Mabillard (IST Austria)

Jan 16, 2015 | 04:00 PM

"What is ... a van Kampen obstruction cocycle"  -- Isaac Mabillard (IST

16:00, Friday, January 16, 2015
@TU MA 313
The Kuratowski theorem provides a nice criterion for graph planarity, ie,
to decide whether a simplicial 1-complex can be embedded into R^2.

A natural generalization of the problem is to find a criterion to decide
whether a simplicial n-complex K can be embedded into R^{2n}. This is what
the van Kampen obstruction cocycle gives us. By using standard tricks in
PL topology, one can show that K is embeddable if and only if (the class
of) its cocycle is zero.

This is (maybe?) surprising because embeddability is a geometric question,
whereas a cocycle is an algebraic object, but it still carries enough
information to solve the geometric problem.

These talks are organized by students for students.

Our goal is to give you the opportunity to enhance your general
mathematical knowledge in a casual atmosphere and meet other PhD and
graduate students across the boundaries of your individual work

Time & Location

Jan 16, 2015 | 04:00 PM

@TU MA 313