Recentring: if the regular element `f` and the chart centre `g` (with division equivalence `Ec`) generate the same ideal modulo `π`, then the chart can be rescaled by a unit so that its new centre `g'
ProvedTypeDensity.division_data_same_cell_recentertype-density
Recentring: if the regular element f and the chart centre g (with division equivalence Ec) generate the same ideal modulo π, then the chart can be rescaled by a unit so that its new centre g' satisfies f = g' + π h₀, with the same curve ideals.
Preamble
import Definitions.Def_TypeDensity_Basic import Definitions.Def_TypeDensity_Measure_AdicCylinders import Mathlib.FieldTheory.RatFunc.Basic import Mathlib.MeasureTheory.Measure.Haar.Unique import Mathlib.NumberTheory.ArithmeticFunction.Moebius import Mathlib.NumberTheory.Padics.PadicIntegers import Mathlib.RingTheory.IntegralClosure.IntegralRestrict import Mathlib.RingTheory.MvPowerSeries.Basic import Mathlib.RingTheory.RamificationInertia.Basic import Mathlib.Topology.Algebra.Nonarchimedean.AdicTopology import Mathlib.Topology.Algebra.MvPolynomial set_option autoImplicit false open TypeDensity open MeasureTheory open scoped BigOperators ENNReal
Formal statement
theorem TypeDensity.division_data_same_cell_recenter (O R : Type) [CommRing O] [CommRing R] [Algebra O R]
[IsLocalRing R] (pi : O) (hpm : algebraMap O R pi ∈ IsLocalRing.maximalIdeal R) (n : ℕ)
(f g : R) (c : Fin n → R)
(hf : Function.Injective (fun y : R ⧸ Ideal.span {algebraMap O R pi} =>
y * Ideal.Quotient.mk (Ideal.span {algebraMap O R pi}) f))
(Ec : R ≃ₗ[O] ((Fin n → O) × R)) (hEc : ∀ s, Ec.symm s = divisionMap g c s)
(hres : Ideal.span {Ideal.Quotient.mk (Ideal.span {algebraMap O R pi}) f} =
Ideal.span {Ideal.Quotient.mk (Ideal.span {algebraMap O R pi}) g}) :
∃ (g' : R) (c' : Fin n → R) (F : R ≃ₗ[O] ((Fin n → O) × R)) (h₀ : R),
(∀ s, F.symm s = divisionMap g' c' s) ∧ f = g' + pi • h₀ ∧
Function.Injective (fun y : R ⧸ Ideal.span {algebraMap O R pi} =>
y * Ideal.Quotient.mk (Ideal.span {algebraMap O R pi}) g') ∧
∀ z : Fin n → O, coordinateIdeal pi g c z = coordinateIdeal pi g' c' z := by sorrySource
TypeDensity/Measure/AdicCylinders.lean#L821-L878