Paper 4, Section II, G

Algebraic Topology
Part II, 2013

(i) State, but do not prove, the Lefschetz fixed point theorem.

(ii) Show that if nn is even, then for every map f:SnSnf: S^{n} \rightarrow S^{n} there is a point xSnx \in S^{n} such that f(x)=±xf(x)=\pm x. Is this true if nn is odd? [Standard results on the homology groups for the nn-sphere may be assumed without proof, provided they are stated clearly.]