🤖 AI Summary
This work investigates how to formalize the notion of one probabilistic model “explaining” another within the framework of generalized probabilistic theories. The authors introduce a concept of explanation based on a specific span structure in the category of probability (Prob) and employ pullback constructions to compose such explanations. Their main contribution is a proof that every locally finite probabilistic model admits a canonical, sharp classical explanation. Furthermore, they establish a canonical functorial mapping from locally finite probabilistic theories to classical—typically nonlocal—theories, thereby demonstrating that generalized probabilistic models are classically interpretable in a precise, structured sense.
📝 Abstract
We introduce a notion of the ``explanation"of one (generalized) probabilistic model by another as particular kind of span in the category $\Prob$ of probabilistic models and morphisms. We show that explanations compose under a standard pullback construction (notwithstanding that $\Prob$ does not support arbitrary pullbacks). We then show that every locally-finite probabilistic model has a canonical, sharp classical explanation. The construction is functorial, so every locally-finite probabilistic theory has a canonical, sharp classical (though of course, usually non-local) representation.