Torus diffeomorphic to $S^1\times S^1$.
111838
Prove that a standard torus is diffeomorphic to $ \mathbb S^1\times \mathbb S^1$
142577
Algebraic proof that a set generated by irrational rotations is dense in $S^1$.
81546
Prove that function from $S^n \times S^m \to 2S^{m+n+1}$ is immersion
83874
Prove that Hopf maps on $S^3, S^2$ and $\mathbb{C} \mathbb{P}^1$ are smooth submersions
27757
$\mathbb{R}\to\mathbb{R}$ Diffeomorphism with special property
95779
Torus and Elliptic curves
103081
Square-tiling a torus
127631
On a conformal mapping
22150
The only 1-manifolds are $\mathbb R$ and $S^1$
110691
Proving that given any two points in a connected manifold, there exists a diffeomorphism taking one to the other
141190
Fundamental group of mapping torus?
74383
How many group structures make $S^1$ a topological group?
64021
Fundamental group of a torus with points removed
62566
Does $X\times S^1\cong Y\times S^1$ imply that $X\times\mathbb R\cong Y\times\mathbb R$?
151735
$\mathbb{R}^3 \setminus A$ deformation retracts onto $S^1 \vee S^2$
147429
Set of points in $\mathbb{C}$ s.t. $z^{n-1} = \overline z$
88155
Show that $[0, 1)\times[0, 1)$ is homeomorphic to $[0, 1]\times[0, 1)$ but not to $[0, 1]\times[0, 1]$.