def
definition
def or abbrev
christoffel
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formal statement (Lean)
13noncomputable def christoffel (g : MetricTensor) : (Fin 4 → ℝ) → Fin 4 → Fin 4 → Fin 4 → ℝ :=
proof body
Definition body.
14 fun x rho mu nu =>
15 (1/2 : ℝ) * Finset.univ.sum (fun (lambda : Fin 4) =>
16 (inverse_metric g) x (fun _ => rho) (fun _ => lambda) * (
17 (partialDeriv_v2 (fun y => g.g y (fun _ => 0) (fun i => if i.val = 0 then mu else lambda)) nu x) +
18 (partialDeriv_v2 (fun y => g.g y (fun _ => 0) (fun i => if i.val = 0 then nu else lambda)) mu x) -
19 (partialDeriv_v2 (fun y => g.g y (fun _ => 0) (fun i => if i.val = 0 then mu else nu)) lambda x)
20 ))
21
22/-- Christoffel symbols are symmetric in the lower indices (torsion-free). -/
used by (30)
-
christoffel -
geodesicEquationHolds -
geodesic_iff_hessianEnergy_EL -
cov_deriv_1_2 -
christoffel_symmetric -
minkowski_christoffel_zero_proper -
minkowski_riemann_zero -
riemann_tensor -
DiscreteContinuumBridge -
FlatChain -
FundamentalTheoremExistence -
IsMetricCompatible -
KoszulIdentity -
levi_civita_metric_compatible -
levi_civita_torsion_free -
LoweredConnectionIdentity -
metric_compatible_of_koszul -
geodesic_uses_real_christoffel -
minkowski_real_christoffel_zero -
RealGeodesic -
rs_eta_symm -
scaffold_agrees_on_minkowski -
SpacelikeGeodesic -
ParallelTransported -
christoffel_quadratic_trace_vanishes -
christoffel_torsion_free -
partialDeriv_christoffel_sym -
riemann_lowered_explicit -
riemann_lowered_explicit_antisym_first -
riemann_trace_vanishes_of_smooth