Does finiteness of the quotient of a compact topological group imply openness of the subgroup?
54346
If $G$ is a compact topological group, how to show that a finite index subgroup of $G$ is open?
112993
Is every quotient of a finite abelian group $G$ isomorphic to some subgroup of $G$?
152825
what are all the open subgroups of $(\mathbb{R},+)$
36631
Is $[0,1] \cap \Bbb Q$ a compact subset of $\Bbb Q$?
147331
Compactness and Hausdorffness
16649
Topological space with countable open cover $\{U_\alpha\} $ with each $U_\alpha$ second-countable, is second countable
148187
Question regarding one-point compactification and homeomorphisms
43711
Categorical Quotient and group actions
143140
When are quotients of homeomorphic spaces homeomorphic?
148403
Compact space and Hausdorff space
121141
Proving Finiteness of Group from Presentation
128334
Question regarding open covers in Zariski topology (distinguished opens of affine schemes are quasi-compact)
128118
Is the cofinite topology on a countable set first countable?
128730
Open subspaces of locally compact Hausdorff spaces are locally compact
70298
Are quotients of chain groups $C_n(X)/C_n(A)$ still free?
58484
Is the topological product $\Pi \{G_\alpha: \alpha < \kappa\} $ a topological group?
107370
An open covering of $\mathbb{Q} \cap [0,1]$ that does not contain any finite subcovering