theorem onsager_reciprocity {N : ℕ} (χ : Fin N → Fin N → ℝ) (hχ : ∀ i j, χ i j = χ j i) (i j : Fin N) : χ i j = χ j i := hχ i j
thesis/CESProofs/Dynamics/GibbsMeasure.lean:410
### Kramers Escape Rate