Lindelöf property and absolute embeddings
1999; American Mathematical Society; Volume: 127; Issue: 3 Linguagem: Inglês
10.1090/s0002-9939-99-04568-2
ISSN1088-6826
Autores Tópico(s)Homotopy and Cohomology in Algebraic Topology
ResumoIt is proved that a Tychonoff space is Lindelöf if and only if whenever a Tychonoff space Y Y contains two disjoint closed copies X 1 X_{1} and X 2 X_{2} of X X , then these copies can be separated in Y Y by open sets. We also show that a Tychonoff space X X is weakly C C -embedded (relatively normal) in every larger Tychonoff space if and only if X X is either almost compact or Lindelöf (normal almost compact or Lindelöf).
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