Successive growth of one-point Riemann spaces #
The local residue argument bounds the jump from L(nP) to L((n+1)P) by
the degree of P. Iterating from L(0) also supplies finite-dimensionality
at every level of the one-point filtration.
theorem
BGS.HasseWeil.finiteExtensionOnePointRiemannSpace_increment
(K : Type u_1)
[Field K]
[Fintype K]
[DecidableEq K]
[DecidableEq (RatFunc K)]
(L : Type u_2)
[Field L]
[Algebra (RatFunc K) L]
[FiniteDimensional (RatFunc K) L]
[Algebra.IsSeparable (RatFunc K) L]
(P : CorvajaZannier.FiniteExtensionPlace K L)
(n : ℕ)
[Module.Finite K ↥(CorvajaZannier.finiteExtensionOnePointRiemannSpace K L P n)]
:
Module.Finite K ↥(CorvajaZannier.finiteExtensionOnePointRiemannSpace K L P (n + 1)) ∧ Module.finrank K ↥(CorvajaZannier.finiteExtensionOnePointRiemannSpace K L P (n + 1)) ≤ Module.finrank K ↥(CorvajaZannier.finiteExtensionOnePointRiemannSpace K L P n) + CorvajaZannier.finiteExtensionPlaceDegree K L P
One step in the one-point filtration is finite-dimensional and has dimension jump at most the degree of the distinguished place.
theorem
BGS.HasseWeil.finiteExtensionOnePointRiemannSpace_moduleFinite
(K : Type u_1)
[Field K]
[Fintype K]
[DecidableEq K]
[DecidableEq (RatFunc K)]
(L : Type u_2)
[Field L]
[Algebra (RatFunc K) L]
[FiniteDimensional (RatFunc K) L]
[Algebra.IsSeparable (RatFunc K) L]
(P : CorvajaZannier.FiniteExtensionPlace K L)
(n : ℕ)
:
Every member of a one-point Riemann filtration is finite-dimensional.
theorem
BGS.HasseWeil.finiteExtensionOnePointRiemannSpace_finrank_succ_le
(K : Type u_1)
[Field K]
[Fintype K]
[DecidableEq K]
[DecidableEq (RatFunc K)]
(L : Type u_2)
[Field L]
[Algebra (RatFunc K) L]
[FiniteDimensional (RatFunc K) L]
[Algebra.IsSeparable (RatFunc K) L]
(P : CorvajaZannier.FiniteExtensionPlace K L)
(n : ℕ)
:
Module.finrank K ↥(CorvajaZannier.finiteExtensionOnePointRiemannSpace K L P (n + 1)) ≤ Module.finrank K ↥(CorvajaZannier.finiteExtensionOnePointRiemannSpace K L P n) + CorvajaZannier.finiteExtensionPlaceDegree K L P
Uniform dimension-jump bound for the one-point filtration.