$S^n$ is not homeomorphic to $S^{n-1}$
39453
How do I prove that $S^n$ is homeomorphic to $S^m \Rightarrow m=n$?
95728
The union of growing circles is not homeomorphic to wedge sum of circles
38378
$M= \{ A \in Mat_{2 \times 2}{\mathbb{R}}| \det(A)=1 \}$ is homeomorphic to $S^{1} \times \mathbb{R}^{2}$
151354
Why are there no non-trivial regular maps $\mathbb{P}^n \to \mathbb{P}^m$ when $n > m$?
85586
Proving $\mathbb{Q}$ isn't homeomorphic to $\mathbb{Z}$
156679
$K[X,Y]/(XY-1)$ not isomorphic to $K[T]$
20383
True or False: there is a space $X$ such that $S^1$ is homeomorphic to $X\times X$
152725
Why does $S^n$ satisfy the local $n$-slice condition? (From Lee's Smooth Manifolds)
62635
Prove that the additive group $ℚ$ is not isomorphic with the multiplicative group $ℚ^*$.
86537
Prove that an open interval and a closed interval are not homeomorphic
121198
$W^{1,1}(\mathbb{R}^n)$ is not compactly embedded in $L^1(\mathbb{R}^n)$?
70198
Why this two spaces do not homeomorphic?
11319
Is $M=\{(x,|x|): x \in (-1, 1)\}$ not a differentiable manifold?
151637
How do we prove that this set is not manifold?
134575
Show that the mapping $f → f~'$ from $C^1([0 , 1])$ to $C([0 , 1])$ is not continuous.
79056
Prove that $\mathbb Z^n$ is not isomorphic to $\mathbb Z^m$ for $m\neq n$
129943
Torsion on $\pi_1(X)$, $X$ connected and open in $\mathbb{R}^n$