$\mathbb{R}^*$ not cyclic
73248
Prove that $\mathbb{R^*}$, the set of all real numbers except $0$, is not a cyclic group
83116
Uncountability of basis of $\mathbb R^{\mathbb N}$
124455
Why multiplicative group $\mathbb{Z}_n^*$ is not cyclic for $n = 2^k$ and $k \ge 3$
112933
Show that $Z\times Z$ is not cyclic...
26764
Proving that $\mathbb R^3$ cannot be made into a real division algebra (and that extending complex multiplication would not work)
43282
Why do $n$ linearly independent vectors span $\mathbb{R}^{n}$?
62793
$\mathbb{R}$ with the lower limit topology is not second-countable
79056
Prove that $\mathbb Z^n$ is not isomorphic to $\mathbb Z^m$ for $m\neq n$
70861
$\mathbb P^n\times \mathbb P^m\not\cong \mathbb P^{m+n}$
22890
Is it coherent to extend $\mathbb{R}$ with a reciprocal of $0$?
71173
Show that $\mathbb{A}^n$ on the Zariski Topology is not Hausdorff, but it is $T_1$
102299
Bijection between $\mathbb{R}^n$ and $\mathbb{R}^m$
119545
Nonzero rationals under multiplication are not a cyclic group
82474
Isometries of $\mathbb{R}^n$
90826
Constructing a subset not in $\mathcal{B}(\mathbb{R})$ explicitly
15909
Bijection from $\mathbb R$ to $\mathbb {R^N}$
108955
Showing $(\mathbb{Q},+)$ is not isomorphic to $(\mathbb{R},+)$