Short and informal version: Does the stable marriage problem have a solution if there are $\kappa$ men and $\kappa$ women for any cardinal $\kappa \geq \aleph_0$?
Long and formal version: Let $\kappa$ be an infinite cardinal. For any set $X$ we set $\text{Bij}(X)$ to be the set of bijections from $X$ to itself.
We are given two "preference functions" $$P_M, P_W: \kappa \to \text{Bij}(\kappa).$$ Let $\mu:M\to W$ be a bijection (also called "marriage"). We say that $(m_0, w_0)\in \kappa\times \kappa$ is a blocking pair for the marriage $\mu$ if
- $\mu(m_0) \neq w_0$, and
- $\big(P_M(m_0)\big)(w_0) < \mu(m_0)$ and vice versa, $\big(P_W(w_0)\big)(m_0) < \mu^{-1}(w_0)$.
A marriage is said to be stable if there are no blocking pairs.
Given $\kappa, P_M, P_W$ as above, is there always a stable marriage?
[This looks so ugly that I'm not even sure it's the correct formalisation, feel free to correct & downvote if I got it wrong.]