New posts in group-theory

A condition for a subgroup of a finitely generated free abelian group to have finite index

Prove that $G \cong\mathrm{Inn}(G)$ if and only if $Z(G)$ is trivial

What is, exactly, a discrete group?

Explanation why an abelian tower admits a cyclic refinement

Bijection between two orbit's spaces

Why $f$ is an automorphism?

Finding the order of the automorphism group of the abelian group of order 8.

Classify all groups containing isomorphic copy of $\mathbb{Z}$ of index $2$.

Existence of deep enough open subgroups in profinite groups

Subgroups of $S_n$ of index $n$ are isomorphic to $ S_{n-1}$

What are the one-parameter subgroups of GL?

Can $\mathbb{R}$ be written as an ascending union of proper additive subgroups?

Are elements commutative when subgroups are?

The number of subgroups of index two in $G$

Are the Groups having all subgroups of same order conjugate classified?

What is this $\Sigma_4 /\langle (12)(34)\rangle$?

Difference between a group normalizer and centralizer

The number of $p$-subgroups of a group

How to check in GAP whether two groups are isomorphic

If $G$ is isomorphic to $H$, then ${\rm Aut}(G)$ is isomorphic to ${\rm Aut}(H)$