New posts in cardinals

Cofinality of an infinite cardinal, alternative definition

Tightness and countable intersection of neighborhoods

Non-existence of a surjection $\aleph_n \to \aleph_{n+1}$, without the axiom of choice

Prove that the set of all monotone functions on $[0,1]$ has same cardinality as $\mathbb R$

Why does $\omega$ have the same cardinality in every (transitive) model of ZF?

Let A = $\left\{1,\:2,\:\left\{1,\:2\right\}\right\}$, how many elements are in the set $P(A)\setminus A$?

Prove that $\mathbb{|Q| = |Q\times Q|}$

Fodor's lemma on singular cardinals

Compact cardinal cannot be successor?

Cardinal of $X^2$

Prove that a field of a set has $2^r$ elements if it has finite cardinality.

Why is the cardinality of irrational numbers greater than rational numbers?

Are there any infinites not from a powerset of the natural numbers?

What is the cardinality of $\omega^\omega$?

Is there a Partition of $[0,1]$ into closed, countably infinite sets?

Cardinality of the infinite sets

Infinite sets and their Cardinality

Is the logarithm of $\aleph_0$ infinite?

Cardinality of the Euclidean topology and the axiom of choice

ZFC + not-CH, can a set with cardinality between $\aleph_0$ and $2^{\aleph_0}$ be defined?