Hatcher-Algebraic-Topology · Problem 4.1.16

Homotopy Theory

Mathematics — Graph Theory · factoring-maps-postnikov

Problem

Show that a map

f : X \to Y

between connected CW complexes factors as a composition

X \to Z_n \to Y

where the first map induces isomorphisms on

\pi_i

for

i \leq n

and the second map induces isomorphisms on

\pi_i

for

i \geq n + 1