Ernst Lindelöf was a Finnish mathematician. Lindelöf spaces in general topology are named after him. A Lindelöf space is a toplogical space for which every open cover has a countable subcover.Recall that a compact space is a topological space for which every open cover has a finite subcover. Hence every compact space is a Lindelöf space.

Note: An open cover for a topological space *X* is a collection,

, of open sets *U* such thatA subcover of

for *X* is a subset of which is also an open cover of *X*.]]>