How to prove $\mathbb{R}\times \mathbb{R}$ is equipotent (i.e. there is a 1-1 map between the two) to $\mathbb{R}$?
14322
Examples of bijective map from $\mathbb{R}^3\rightarrow \mathbb{R}$
1117
Is there a bijection between $(0,1)$ and $\mathbb{R}$ that preserves rationality?
115270
What are the generators of $(\mathbb{R},+)$?
71767
What is the difference between $\Bbb{R^n}\times\Bbb{R^m}$ and $\Bbb{R^{m+n}}$?
128989
Is ${\bf Z} \times {\bf Z}$ elementarily equivalent to ${\bf Z}$?
90239
$\mathbb{Z} \times \mathbb{Z}$ is cyclic.
143800
continuous map on $\mathbb{R}$ which is the identity on $\mathbb{Q}$ is the identity map, hence Aut$(\mathbb{R}/\mathbb{Q})= 1.$
156910
Necessary and sufficient condition for $R/IJ \cong R/I \times R/J$
45179
When does the isomorphism $G\simeq \ker(\phi)\times \operatorname{im}(\phi)$? hold?
94059
Extending a Homotopy from $X \times [0,1]$ to $X \times \mathbb{R}$
5250
Are $T\mathbb{S}^2$ and $\mathbb{S}^2 \times \mathbb{R}^2$ different?
114916
$\mathbb Z_{mn}$ isomorphic to $\mathbb Z_m\times\mathbb Z_n$ whenever $m$ and $n$ are coprime
15733
Show that the cardinality of $\mathbb N$ is the same as the cardinality of $\mathbb N \times \mathbb N$
11259
Prove $R\times S$ is not an integral domain
64130
Prove that $\mathbb{Q}^{\times}$ not isomorphic to $\mathbb{Z}^{n}$
108955
Showing $(\mathbb{Q},+)$ is not isomorphic to $(\mathbb{R},+)$
61103
Prove that $\mathbb{|Q| = |Q\times Q|}$