Manifolds: Hausdorffness versus homogeneity
  We analyze the relationship between Hausdorffness and homogeneity in the frame of manifolds, not confined to be Hausdorff. We exhibit examples of homogeneous non-Hausdorff manifolds and prove that a Lindel\"of homogeneous manifold is Hausdorff. 
Mathieu Baillif and Alexandre Gabard