Joint analyticity of Kepler's equation #
The existing one-variable inverse theorem gives analyticity of the eccentric anomaly in mean
anomaly for fixed eccentricity. Poincaré's coefficient argument also needs analytic dependence
on eccentricity. We obtain it by applying the analytic inverse-function theorem to the triangular
map (e, E) ↦ (e, E - e sin E).
Kepler's equation while retaining eccentricity as a coordinate.
Equations
- LeanPool.PoincareThreeBody.eccentricKeplerMap parameters = (parameters.1, LeanPool.PoincareThreeBody.eccentricMeanAnomaly parameters.1 parameters.2)
Instances For
theorem
LeanPool.PoincareThreeBody.hasFDerivAt_eccentricKeplerMap
(parameters : ℝ × ℝ)
:
HasFDerivAt eccentricKeplerMap (eccentricKeplerMapFDeriv parameters) parameters
theorem
LeanPool.PoincareThreeBody.analyticAt_eccentricKeplerMap
(parameters : ℝ × ℝ)
:
AnalyticAt ℝ eccentricKeplerMap parameters
theorem
LeanPool.PoincareThreeBody.eccentricKeplerMapFDeriv_bijective
{parameters : ℝ × ℝ}
(hdenominator : 1 - parameters.1 * Real.cos parameters.2 ≠ 0)
:
Function.Bijective ⇑(eccentricKeplerMapFDeriv parameters)
Eccentricity and eccentric anomaly as a joint function of eccentricity and mean anomaly.
Equations
- LeanPool.PoincareThreeBody.jointEccentricAnomaly parameters = (parameters.1, LeanPool.PoincareThreeBody.eccentricAnomaly parameters.1 parameters.2)
Instances For
theorem
LeanPool.PoincareThreeBody.eccentricKeplerMap_jointEccentricAnomaly
{parameters : ℝ × ℝ}
(heccentricity : 0 ≤ parameters.1)
:
theorem
LeanPool.PoincareThreeBody.analyticAt_jointEccentricAnomaly
{parameters : ℝ × ℝ}
(heccentricity : 0 < parameters.1)
(heccentricityOne : parameters.1 < 1)
:
AnalyticAt ℝ jointEccentricAnomaly parameters
The eccentric anomaly is jointly real analytic in eccentricity and mean anomaly throughout
the elliptic range 0 < e < 1.
theorem
LeanPool.PoincareThreeBody.analyticAt_eccentricAnomaly_joint
{eccentricity meanAnomaly : ℝ}
(heccentricity : 0 < eccentricity)
(heccentricityOne : eccentricity < 1)
:
AnalyticAt ℝ (fun (parameters : ℝ × ℝ) => eccentricAnomaly parameters.1 parameters.2) (eccentricity, meanAnomaly)