Topology

From Maths
Revision as of 18:45, 27 February 2015 by Alec (Talk | contribs)

Jump to: navigation, search

Once you have understood metric spaces you can read motivation for topology and see why topological spaces "make sense" and extend metric spaces.

Phrases

Let (X,J) and (X,K) be two topologies on X

Coaser, Smaller, Weaker

Given two topologies J

, K
on X we say:
J
is coaser, smaller or weaker than K
if JK

Smaller is a good way to remember this as there are 'less things' in the smaller topology.

Finer, Larger, Stronger

Given two topologies J

, K
on X we say:
J
is finer, larger or stronger than K
if JK

Larger is a good way to remember this as there are 'more things' in the larger topology.