Trivial topology
From Maths
Definition
The trivial topology (sometimes known as the indiscrete topology[1])is an example of a topological space that exists for any set X, it is defined as follows[1]:
- Given a set X we define the open sets as J:={∅,X}
Then (X,J) is a topology.
Contrast to the Discrete topology
There is at least 1 other topology that can be defined on an arbitrary set, the Discrete topology, which is a topology induced by a metric, the Discrete metric specifically.
Warning, the following is Alec's speculation
- Unlike the discrete topology the indiscrete, or trivial topology is not induced by a metric. For if such a metric existed it would have to have the open ball of radius 0 as the entire of X, then no strict :subset of X (except the emptyset) is a neighborhood to all of its points, thus not open.
- However this is not a metric as the metric must assign two points a distance of 0 if and only if they are the same point.
- I'm not entirely happy about this proof, however there is logic here! I will do this formally later.
TODO: Formally prove this
End of warning
References
- ↑ Jump up to: 1.0 1.1 Topology - James R. Munkres - Second Edition