Clicked on the article because I thought it would discuss the topology of the universe, i.e. whether (a spatial slice of) the universe is open (non-compact and

Clicked on the article because I thought it would discuss the topology of the universe, i.e. whether (a spatial slice of) the universe is open (non-compact and without boundary) or closed (compact[0] and without boundary) or something else. :( [0]: In particular, it would be of finite volume.