Kincaid MacDonald will present his General Exam "Epistemic Empowerment and Belief Curvature in LLM Agents" on May 14, 2026 at 1pm in 306 Sherrerd Hall and Zoom.
Committee: Peter Henderson (advisor), Aleksandra Korolova, Tom Griffiths
Abstract
We study the agentic behavior of LLMs through the geometry of their beliefs, viewing reasoning trajectories as paths traced across a manifold of belief representations. This opens a quantitative window on fickle matters of agentic temperament, like a model's tendency to fixate on one hypothesis, or its capacity to take actions that challenge its beliefs. Both of these are captured by epistemic empowerment, a measure of empowerment in belief space. We prove that the epistemic empowerment is upper-bounded by the local curvature of the model's beliefs, and devise a curvature estimator which is more accurate than existing methods in high dimensions. Using this, we can measure LLM's epistemic empowerment and increase it through RL fine-tuning, resulting in increased performance on tests of exploration capacity and open-mindedness. We also posit that an agent high in epistemic empowerment makes a better collaborator than one high in traditional empowerment.