Atlas of manifold

  1. I was thinking about something yesterday and I couldn't quite figure it out. It's about the question if an atlas is a countable set. Because we know that every manifold is second countable, so it has a countable basis. But does every element of the basis fit inside a chart domain? If that's the case then the atlas is countable. But I'm not sure that's the case :)
  2. jcsd
  3. George Jones

    George Jones 6,385
    Staff Emeritus
    Science Advisor
    Gold Member

    Each n-sphere S^n is covered by an atlas that has 2 members.

    Do you mean maximal atlas?

  4. Not only that but manifolds aren't necessarily second countable. It depends on the author. If you start with a set M, and put a complete smooth atlas on it (so I'm talking about differentiable manifolds in this context), then the charts form a basis for the topology on the M and that topology isn't necessarily second countable.

Know someone interested in this topic? Share a link to this question via email, Google+, Twitter, or Facebook

Have something to add?