The weight and Lindelöf property in spaces and topological groups

Several facts about subspaces of Hausdorff separable spaces are established. It is well known that the weight of a separable Hausdorff space X can be as big as 22c. We prove on the one hand that if a regular Lindelöf Σ-space Y is a subspace of a separable Hausdorff space, then w(Y)≤2ω, and the same conclusion holds for a Lindelöf P-space Y. On the other hand, we present an example of a countably compact topological Abelian group G which is homeomorphic to a subspace of a separable Hausdorff space and satisfies w(G)=22c, i.e. G has the maximal possible weight.