Topological Crystals (Part 2)

We’re building crystals, like diamonds, purely from topology. Last time I said how: you take a graph and embed its maximal abelian cover into the vector space Now let me say a bit more about the maximal abelian cover. It’s not nearly as famous as the universal cover, but it’s very nice.

First I’ll whiz though the basic idea, and then I’ll give the details.

The basic idea

By ‘space’ let me mean a connected topological space that’s locally nice. The basic idea is that if is some space, it...