Difference between revisions of "Lindelöf number"
From Encyclopedia of Mathematics
(Start article: Lindelöf number) |
(→References: isbn link) |
||
| Line 6: | Line 6: | ||
====References==== | ====References==== | ||
| − | * Mary Ellen Rudin, ''Lectures on Set Theoretic Topology'', American Mathematical Society (1975) ISBN 0-8218-1673-X | + | * Mary Ellen Rudin, ''Lectures on Set Theoretic Topology'', American Mathematical Society (1975) {{ISBN|0-8218-1673-X}} |
Latest revision as of 11:55, 23 November 2023
2020 Mathematics Subject Classification: Primary: 54A25 [MSN][ZBL]
density character
One of the cardinal characteristics of a topological space. The least infinite cardinal number $\tau$ such that every open covering has a subcovering of cardinality at most $\tau$.
References
- Mary Ellen Rudin, Lectures on Set Theoretic Topology, American Mathematical Society (1975) ISBN 0-8218-1673-X
How to Cite This Entry:
Lindelöf number. Encyclopedia of Mathematics. URL: http://encyclopediaofmath.org/index.php?title=Lindel%C3%B6f_number&oldid=54583
Lindelöf number. Encyclopedia of Mathematics. URL: http://encyclopediaofmath.org/index.php?title=Lindel%C3%B6f_number&oldid=54583