Relation between Product and Box Topology

Tychonoff Topology

 * Leigh.Samphier/Sandbox/Product Space is Product in Category of Topological Spaces where it is shown that the Tychonoff topology is the topology on the cartesian product of topological spaces that defines the categorical product in the category of topological spaces. The Tychonoff topology is therefore important in a categorical sense.


 * Tychonoff Topology is Coarsest Topology such that Projections are Continuous where it is shown that the Tychonoff topology is the coarsest topology on the cartesian product of topological spaces for which the projections are continuous.

Natural Basis of Tychonoff Topology

 * Leigh.Samphier/Sandbox/Natural Basis of Tychonoff Topology where it is shown that the natural basis on $X$ is the set $\BB$ of cartesian products of the form $\displaystyle \prod_{i \mathop \in I} U_i$ where:
 * for all $i \in I : U_i \in \tau_i$
 * for all but finitely many indices $i : U_i = X_i$


 * Leigh.Samphier/Sandbox/Natural Basis of Tychonoff Topology of Finite Product where it is shown that the natural basis on $\displaystyle X = \prod_{k \mathop = 1}^n X_k$ is:
 * $\BB = \set{\displaystyle \prod_{k \mathop = 1}^n U_k : \forall k : U_k \in \tau_k}$

Box Topology

 * Basis for Box Topology where it is shown that the extension of the characterisation of the natural basis for the Tychonoff topology on a finite cartesian product to an arbitrary product is a basis and therefore the box topology is a topology.


 * Leigh.Samphier/Sandbox/Box Topology may not form Categorical Product in the Category of Topological Spaces, the box topology on the cartesian product of topological spaces does not always give us the categorical product in the category of topological spaces.


 * Leigh.Samphier/Sandbox/Box Topology may not be Coarsest Topology such that Projections are Continuous where it is shown that the box topology is not in general the coarsest topology on the cartesian product of topological spaces for which the projections are continuous.


 * Leigh.Samphier/Sandbox/Box Topology contains Tychonoff Topology where it is shown that the box topology is a finer topology than the Tychonoff topology.


 * Box Topology on Finite Product Space is Tychonoff Topology where it is shown that the box topology and the Tychonoff topology are the same topology on a finite cartesian product of topological spaces. So the box topology is only of interest for an arbitrary or infinite product of topological spaces.

Other pages

 * Universal Property of Product of Topological Spaces
 * Leigh.Samphier/Sandbox/Definition:Product Space (Topology)