OAI/MathematicalPhysics/Boltzmann/Branching/VariableSurvival.lean
2 declarations, 0 contain sorry, 0 declared as axioms
Positive characteristic forcing with an integrable loss frequency
- theorem
OAI.BoltzmannNonuniqueness.TransportPrimitive.exp_absolutelyContinuousline 10 - theorem
OAI.BoltzmannNonuniqueness.TransportPrimitive.variable_survival_with_sourceline 22Source documentation
The integrating factor keeps the positive forcing when the frequency is only integrable.
theorem variable_survival_with_source {T : ℝ} (hT : 0 ≤ T) {u r k g : ℝ → ℝ} (hu : AbsolutelyContinuousOnInterval u 0 T) (hk : IntervalIntegrable k volume 0 T) (hg : IntervalIntegrable g volume 0 T) (hr : ∀ᵐ t, t ∈ Icc 0 T → HasDerivAt u (r t) t) (hb : ∀ᵐ t, t ∈ Icc 0 T → g t-k t*u t ≤ r t) : Real.exp (-(∫ t in 0..T, k t))*u 0 + (∫ t in 0..T, Real.exp (-((∫ s in 0..T, k s)-(∫ s in 0..t, k s)))*g t) ≤ u T := by …