Tangential homotopy equivalences (Ex)
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# Give an example of a tangential homotopy equivalence which is not homotopic to a diffeomorphism. | # Give an example of a tangential homotopy equivalence which is not homotopic to a diffeomorphism. | ||
# Show that if $f \colon M \to N$ is a tangential homotopy equivelance, then there is a diffeomorphism | # Show that if $f \colon M \to N$ is a tangential homotopy equivelance, then there is a diffeomorphism | ||
− | $$ F \colon D^n \times M \cong D^n \times N | + | $$ F \colon D^n \times M \cong D^n \times N$$ |
+ | such that $p_n \circ F|_{0 \times M}$ is homotopic to $f$, where $p_N \colon D^n \times N \to N$ is the projection. | ||
{{endthm}} | {{endthm}} | ||
</wikitex> | </wikitex> |
Revision as of 23:51, 25 August 2013
A homotopy equivalence of closed smooth -manifolds is called tangential if ; i.e. pulls back the tangent bundle of to .
Example 0.1.
- Give an example of a tangential homotopy equivalence which is not homotopic to a diffeomorphism.
- Show that if is a tangential homotopy equivelance, then there is a diffeomorphism
such that is homotopic to , where is the projection.