Trivial topology
The trivial topology , indiscreet topology , chaotic topology or cluster topology is a structure considered in the mathematical sub-area of topology for a set that makes it a topological space .
definition
Be a lot. The trivial topology on is the topology where only the set and the empty set are open .
properties
Let a topological space be provided with the trivial topology.
- All points in are topologically indistinguishable .
- According to the definition, only the empty set and the whole set are closed .
- The space is compact and therefore paracompact , lindelöf and locally compact .
- The space is path-connected , because every mapping of a topological space is continuous and therefore also connected .
- The trivial topology is the coarsest of all topologies on a given set; in particular, every mapping from a topological space into a trivial topology is continuous .
- The trivial topology has all the usual separation properties , unless they require T₀ , and can be pseudometrized by the pseudometrics, which assigns the distance 0 to any two points.
- Each filter converges towards each point in the trivial topology; this characterizes the trivial topology.
See also
Individual evidence
- ↑ Trivial topology. In: Guido Walz (Red.): Lexicon of Mathematics. Volume 5: Sed to Zyl. Spectrum - Akademischer Verlag, Heidelberg et al. 2002, ISBN 3-8274-0437-1 .
- ↑ Lothar Tschampel: BUCHMAT. 3.A: Topology 1. General topology. Version 2. Buch-X-Verlag, Berlin 2011, ISBN 978-3-934671-60-7 .
- ↑ Harro Heuser : Textbook of Analysis . 13th revised edition. tape 2 . Teubner, Stuttgart et al. 2004, ISBN 3-519-62232-7 , pp. 210 .
- ^ A b Gerd Laures, Markus Szymik: Basic course topology . Spectrum - Akademischer Verlag, Heidelberg 2009, ISBN 978-3-8274-2040-4 , p. 9 .