I just attended a lecture by Rami Grossberg and he mentioned that he is not aware of any applications of Morley's Categoricity Theorem. This is exactly my question.

**Question:** Do you know of any applications of Morley's Categoricity Theorem outside of Logic?

**Morley's Categoricity Theorem** If $T$ is a first-order theory in a countable vocabulary and $T$ is categorical in one uncountable cardinal, then it is categorical in all uncountable cardinals.