34 let a := 1 / (1 + z) 35 -- Simplified ODE form in terms of z or λ 36 ∀ z', deriv (deriv DA_func) z' + (Upsilon P a) * ricci_focusing * DA_func z' = 0 37 38/-- Angular diameter distance D_A under optical rescaling. 39 Modeled as the background distance rescaled by the Upsilon factor. -/
depends on (9)
Lean names referenced from this declaration's body.