26 lines
1.0 KiB
Markdown
26 lines
1.0 KiB
Markdown
# Math4202 Topology II Exam 1 Practice
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In the following, please provide complete proof of the statements and the answers you give. The total score is 25 points.
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## Problem 1
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- (2 points) State the definition of a topological manifold.
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- (2 points) Prove that real projective space $RP^2$ is a manifold.
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- (2 points) Find a 2-1 covering space of $RP^2$.
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Problem 2
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- (2 points) State the definition of a CW complex.
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- (4 points) Describe a CW complex homeomorphic to the 2-torus.
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Problem 3
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- (2 points) State the definition of the fundamental group of a topological space $X$ relative to $x_0 \in X$.
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- (4 points) Compute the fundamental group of $R^n$ relative to the origin.
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Problem 4
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- (2 points) Give a pair of spaces that are homotopic equivalent, but not homeomorphic.
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- (4 points) Let $A$ be a subspace of $R^n$, and $h : (A, a_0) \to (Y, y_0)$. Show that if $h$ is extendable to a continuous map of $R^n$ into $Y$, then
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$$h_* : \pi_1(A, a_0) \to \pi_1(Y, y_0)$$
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is the trivial homomorphism (the homomorphism that maps everything to the identity element). |