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corrected mental bug.
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Igor Rivin
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As a topological space, this is homotopy equivalent to $\mathbb{S}^2,$$\mathbb{D}^3,$ so the homotopy groups are whatever they are for $\mathbb{S}^2.$$\mathbb{D}^3.$ As an orbifold, the fundamental group is $\mathbb{PSL}(2, \mathbb{Z}),$ while the higher homotopy groups vanish, since the universal cover is $\mathbb{H}^3.$

NOTE Thanks to HJRW for the correction.

As a topological space, this is homotopy equivalent to $\mathbb{S}^2,$ so the homotopy groups are whatever they are for $\mathbb{S}^2.$ As an orbifold, the fundamental group is $\mathbb{PSL}(2, \mathbb{Z}),$ while the higher homotopy groups vanish, since the universal cover is $\mathbb{H}^3.$

As a topological space, this is homotopy equivalent to $\mathbb{D}^3,$ so the homotopy groups are whatever they are for $\mathbb{D}^3.$ As an orbifold, the fundamental group is $\mathbb{PSL}(2, \mathbb{Z}),$ while the higher homotopy groups vanish, since the universal cover is $\mathbb{H}^3.$

NOTE Thanks to HJRW for the correction.

Source Link
Igor Rivin
  • 96.4k
  • 11
  • 153
  • 366

As a topological space, this is homotopy equivalent to $\mathbb{S}^2,$ so the homotopy groups are whatever they are for $\mathbb{S}^2.$ As an orbifold, the fundamental group is $\mathbb{PSL}(2, \mathbb{Z}),$ while the higher homotopy groups vanish, since the universal cover is $\mathbb{H}^3.$