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Algebraic Topology
· Problem 25
The Fundamental Group — Allen Hatcher
Mathematics — Topology · suspension
Problem
If
X
X
X
is a CW complex with components
X
α
X_\alpha
X
α
, show that the suspension
S
X
SX
S
X
is homotopy equivalent to
Y
∨
α
S
X
α
Y \vee_\alpha SX_\alpha
Y
∨
α
S
X
α
for some graph
Y
Y
Y
. In the case that
X
X
X
is a finite graph, show that
S
X
SX
S
X
is homotopy equivalent to a wedge sum of circles and 2-spheres.
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