- #1
Bacle
- 662
- 1
Hi again:
I was trying to use Mayer-Vietoris to compute the homology of CP^1 , the
complex projective 1-space embedded in C^2-{(0,0)}. ( I know cellular
homology would have been much easier, but I am trying to practice using M.-V).
Problem is , I need to get a(n) topological S^1 somewhere , in either A,B or A/\B,
and a contractible space, but I don't see where I can get the S^1 from.
The sets A,B I am using I think are the standard charts for CP^1 as a manifold:
We have :
1) A= [z1,z2] : z1 not 0 (with the chart map [z1,z2]-->z2/z1
2) B=[z1,z2] :z2 not 0 (chart map is z1/z2)
I think A/\B (intersection) consists of the 16 open cuadrants of R^4 ,
and each of these intersections (implying that each of A,B is contractible)
, but I do not see how A/\B is a topological S^1 .
Any Ideas.?
I was trying to use Mayer-Vietoris to compute the homology of CP^1 , the
complex projective 1-space embedded in C^2-{(0,0)}. ( I know cellular
homology would have been much easier, but I am trying to practice using M.-V).
Problem is , I need to get a(n) topological S^1 somewhere , in either A,B or A/\B,
and a contractible space, but I don't see where I can get the S^1 from.
The sets A,B I am using I think are the standard charts for CP^1 as a manifold:
We have :
1) A= [z1,z2] : z1 not 0 (with the chart map [z1,z2]-->z2/z1
2) B=[z1,z2] :z2 not 0 (chart map is z1/z2)
I think A/\B (intersection) consists of the 16 open cuadrants of R^4 ,
and each of these intersections (implying that each of A,B is contractible)
, but I do not see how A/\B is a topological S^1 .
Any Ideas.?