Is $\widehat{\mathbb{R}/\mathbb{Z}} = \mathbb{Z}$?
113898
Why is that $\widehat{\mathbb{R}/\mathbb{Z}}\cong\mathbb{Z}$?
51687
Is the set $ \ (\mathbb{Z}_p \setminus \mathbb{Z}) \cap \mathbb{Q}$ non-empty?
152451
REVISITED $^2$: Does a solution in $\mathbb{R}^n$ imply a solution in $\mathbb{Q}^n$?
75970
$\mathbb Z[1/2]$ is not finitely generated?
131082
Proof that $\mathbb R/[0,1]$ and $\mathbb R$ are homeomorphic
139934
In $\mathbb{Z}/(n)$, does $(a) = (b)$ imply that $a$ and $b$ are associates?
12743
$\bigodot=?$ for $(\sqrt 2) ^ \sqrt 3 \bigodot (\sqrt 3) ^ \sqrt 2$ where $\bigodot is \lt or \gt$
102299
Bijection between $\mathbb{R}^n$ and $\mathbb{R}^m$
80202
Why is $[0, 1] \cap \mathbb{Q}$ not compact in $\mathbb{Q}$?
29452
Divisor in $\mathbb{C}[X]$ $\implies$ divisor in $\mathbb{R}[X]$?
74663
Is $\mathbb{R}$ an algebraic extension of some proper subfield?
138258
What is the injective envelope of $\mathbb{Z}/n\mathbb{Z}$?
42810
Is $(\mathbb{Q},+)$ isomorphic to $(\mathbb{Q}^n,+)$?
96363
How to show that $\mathbb R^n$ with the $1$-norm is not isometric to $\mathbb R^n$ with the infinity norm for $n>2$?
27188
Bijection between $\mathbb{R}$ and $\mathbb{R}/\mathbb{Q}$
61375
Meaning of $\mathbb{R}[x]$
83001
Easier way to show $(\mathbb{Z}/(n))[x]$ and $\mathbb{Z}[x] / (n)$ are isomorphic