This paper establishes a finite information-geometric formulation of observer entropy defined via Kullback–Leibler divergence under coarse-graining. The main result (Bridge Theorem) proves the local expansion Sₒbs (pₜheta, eps) = (1/2) eps² vT I (theta*) v + O (eps³), showing that observer entropy is governed at leading order by the Fisher information matrix. All results are derived in a fully finite setting with explicit regularity assumptions. An exact softmax example and a resolution–information trade-off are provided.
Vladimir Khomyakov (Sun,) studied this question.