$\sigma$-algebra with cardinality $\aleph_0$
117133
Is there an infinite countable $\sigma$-algebra on an uncountable set
122947
What is the cardinality of the set of infinite cardinalities?
127233
Cardinality of order types in $\mathbb{N}$
150605
Existence of a regular uncountable $\aleph_{\alpha}$ without $\mathsf{AC}$
120442
Prove Borel sigma-algebra translation invariant
9651
Cardinality of cartesian product of an infinite set with N
74162
Show intersection of two algebras are not a $\sigma$-algebra
129813
Is there an easy proof for ${\aleph_\omega} ^ {\aleph_1} = {2}^{\aleph_1}\cdot{\aleph_\omega}^{\aleph_0}$?
50241
Cardinality of the quotient ring $\mathbb Z_5[i]/\langle 1+i\rangle$
83830
Sigma algebra generated by the set of all singletons
142145
strictly positive elements in $C^*$-algebra
89167
Cardinality of equivalence relations in $\mathbb{N}$
110450
probability measure on $\sigma$-algebra
55157
$\sigma$-algebras on a countable set is generated by partitions of the set
144359
A random variable that induces a $\sigma$-algebra the same as the one in the sample space
62687
Proving Cardinality of Cosets in Abstract Algebra
81509
The cardinality of a countable union of countable sets, without the axiom of choice