Finite fundamental group in the Euclidean space
129943
Torsion on $\pi_1(X)$, $X$ connected and open in $\mathbb{R}^n$
131519
intuition on the fundamental group of $S^1$
94708
Non-orientable 3-manifold has infinite fundamental group
84132
Number of preimages of a group element under a homomorphism.
81471
Finite dimensional spaces
58937
Finite Index of Subgroup of Subgroup
85222
Direct sum of finitely-many non-abelian groups
153204
Euclidean domain $\mathbb{Z}[\sqrt{d}]$
61226
Group Structure on $\Bbb R$
26256
Characterizing Dense Subgroups of the Reals
149029
3-manifold examples of homomorphisms between fundamental groups that are not induced by continuous maps
64408
Subgroup of $\mathbb{Q}$ with finite index
58135
Quotient group $SL(2,\mathbb{R})/SO(2,\mathbb{R})$
55652
Fundamental group of the torus
2064
Finite subgroups of orthogonal transformations in $\mathbb{R}^3$
55070
Fundamental group of complement of $n$ lines through the origin in $\mathbb{R}^3$
27670
Group homomorphisms $\mathbb{Q}\to\mathbb{R}$