This came up in the question about Eilenberg-MacLane spaces. Given the definition of K(G, n), it's easy to prove that there is a map K(G,n) x K(G,n) --> K(G,n) that endows cohomology with an additive structure.

Question: what's the most geometric way to show the existence of maps K(G,n) x K(G,m) --> K(G,n+m) that endow cohomology with multiplicative structure?

This came up in the question about Eilenberg-MacLane spaces. Given the definition of K(G, n), it's easy to prove that there is a map K(G,n) x K(G,n) --> K(G,n) that endows cohomology with an additive structure.

Question: what's the most geometric way to show the existence of maps K(G,n) x K(G,m) --> K(G,n+m) that endow cohomology with multiplicative structure?

This came up in the question about Eilenberg-MacLane spaces. Given the definition of K(G, n), how to show geometrically that there are maps K(G,n) x K(G,m) --> K(G,n+m) that endow cohomology with multiplicative structure?

This came up in the question about Eilenberg-MacLane spaces. Given the definition of K(G, n), it's easy to prove that there is a map K(G,n) x K(G,n) --> K(G,n) that endows cohomology with an additive structure.

Question: what's the most geometric way to show the existence of maps K(G,n) x K(G,m) --> K(G,n+m) that endow cohomology with multiplicative structure?