Results 1 to 3 of 3

Math Help - Sphere...

  1. #1
    TTB
    TTB is offline
    Junior Member
    Joined
    Aug 2009
    Posts
    26

    Sphere...

    Hi - please delete this thread. I have solved the question myself & without the post made by aiw.

    Therefore this post will be of no use to anyone else - please could you delete it.

    Thank you x
    Last edited by TTB; November 24th 2009 at 08:54 PM.
    Follow Math Help Forum on Facebook and Google+

  2. #2
    Senior Member
    Joined
    Nov 2008
    Posts
    394
    Quote Originally Posted by TTB View Post
    How do I show that the join [http://en.wikipedia.org/wiki/Join_(topology) Intuitively it is formed by taking the disjoint union of the two spaces and attaching a line segment joining every point in A to every point in B] of the spheres S^n-1 and S^m-1 is the sphere S^(m+n)?

    PS - I have an embedding from the join of a copact subset of S^n-1 & a compact snset of S^m-1 to the m+n-dim Euclidean plane, but not sure if that is needed for the above problem or if so how to use it.
    Isn't join of the spheres S^{n-1} and S^{m-1} is the sphere S^{n+m-1}? By the definition of join, you have an embedding f:S^{n-1} \rightarrow S^{n+m-1} and g:S^{m-1} \rightarrow S^{n+m-1}, since S^{n-1} can be embedded into (S^{n-1} \times S^{m-1} \times \{0\})/S^{m-1} and S^{m-1} can be embedded into (S^{n-1} \times S^{m-1} \times \{1\})/S^{n-1}.
    Follow Math Help Forum on Facebook and Google+

  3. #3
    TTB
    TTB is offline
    Junior Member
    Joined
    Aug 2009
    Posts
    26
    It's ok, I think I've sorted it out now.

    Thanks anyway. x
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. sphere
    Posted in the Pre-Calculus Forum
    Replies: 5
    Last Post: July 26th 2011, 10:43 AM
  2. Sphere
    Posted in the Geometry Forum
    Replies: 1
    Last Post: March 23rd 2010, 09:03 AM
  3. Sphere
    Posted in the Geometry Forum
    Replies: 1
    Last Post: March 23rd 2010, 03:30 AM
  4. Sphere...
    Posted in the Geometry Forum
    Replies: 6
    Last Post: December 2nd 2007, 10:12 PM
  5. Sphere
    Posted in the Calculus Forum
    Replies: 1
    Last Post: September 11th 2007, 06:37 PM

Search Tags


/mathhelpforum @mathhelpforum