Lucia Martin Merchan, Department of Pure Mathematics, University of Waterloo
"A compact non-formal closed G2 manifold with b1=1"
A G2 structure on a 7-dimensional Riemannian manifold (M,g) is determined by a stable of 3-form φ. It is said to be closed if dφ=0 and torsion-free if φ is parallel. The purpose of the talk is understanding certain topological properties of compact manifolds with a closed G2 structure that cannot be endowed with any torsion-free G2 structure. Namely, we outline the construction of such a manifold that is non-formal and has first Betti number b1=1.