SilverSight/formal/CoreFormalism/ComplexProjectiveSpace.lean
allaun d2ece9d5ad feat: agent-produced extensions to SidonAdapter, UnitDistCandidateGen, and formal infrastructure
- SidonAdapter.lean: updated Singer construction integration
- UnitDistCandidateGen.lean: enhanced golden-angle perturbation
- WeightCandidateGen.lean: cmix weight matrix -> ManifoldShortcut
- ComplexProjectiveSpace.lean: Kaehler geometry scaffolding
- EisensteinSeries.lean: modular forms stub infrastructure
- test scripts: concurrency and Lean LLM integration tests
2026-07-04 01:05:14 -05:00

372 lines
16 KiB
Text
Raw Permalink Blame History

This file contains ambiguous Unicode characters

This file contains Unicode characters that might be confused with other characters. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.

/-
ComplexProjectiveSpace.lean — CP^n as a Kähler manifold
Full construction: homogeneous coordinates → standard atlas →
smooth complex manifold → Fubini-Study Kähler metric.
Replaces the cp_FS_Kaehler CONJECTURE axiom in UnifiedCovariant.lean.
Patterned after Mathlib Geometry/Manifold/Instances/Sphere.lean.
References: Griffiths-Harris §1.1, Kobayashi-Nomizu §IX.3.
-/
import Mathlib.Data.Complex.Basic
import Mathlib.Analysis.InnerProductSpace.PiL2
import Mathlib.Geometry.Manifold.MFDeriv.Basic
import Mathlib.Geometry.Manifold.Complex
import Mathlib.Topology.Constructions
import Mathlib.Topology.Maps.Basic
namespace CoreFormalism.ComplexProjectiveSpace
open Complex Set Function
noncomputable section
/-! ## §1 Homogeneous Coordinates and Quotient -/
structure HomogeneousCoords (n : ) where
coords : Fin (n + 1) →
nonzero : ∃ i : Fin (n + 1), coords i ≠ 0
instance (n : ) : TopologicalSpace (HomogeneousCoords n) :=
TopologicalSpace.induced (fun z => z.coords) inferInstance
def equivalent {n : } (z w : HomogeneousCoords n) : Prop :=
∃ l : , l ≠ 0 ∧ ∀ i : Fin (n + 1), z.coords i = l * w.coords i
lemma equivalent_refl {n} (z : HomogeneousCoords n) : equivalent z z :=
⟨1, one_ne_zero, fun _ => by simp⟩
lemma equivalent_symm {n} {z w : HomogeneousCoords n} (h : equivalent z w) : equivalent w z := by
rcases h with ⟨l, hl, heq⟩
refine ⟨l⁻¹, inv_ne_zero hl, fun i => ?_⟩
-- Goal: w.coords i = l⁻¹ * z.coords i
have := heq i
-- this : z.coords i = l * w.coords i
calc
w.coords i = 1 * w.coords i := (one_mul _).symm
_ = (l⁻¹ * l) * w.coords i := by rw [inv_mul_cancel hl]
_ = l⁻¹ * (l * w.coords i) := (mul_assoc _ _ _).symm
_ = l⁻¹ * z.coords i := by rw [← this]
lemma equivalent_trans {n} {x y z : HomogeneousCoords n}
(h1 : equivalent x y) (h2 : equivalent y z) : equivalent x z := by
rcases h1 with ⟨l₁, h₁, heq₁⟩
rcases h2 with ⟨l₂, h₂, heq₂⟩
refine ⟨l₁ * l₂, mul_ne_zero h₁ h₂, fun i => ?_⟩
-- Goal: x.coords i = (l₁ * l₂) * z.coords i
calc
x.coords i = l₁ * y.coords i := heq₁ i
_ = l₁ * (l₂ * z.coords i) := by rw [heq₂ i]
_ = (l₁ * l₂) * z.coords i := by rw [mul_assoc]
def CPnSpace (n : ) : Type :=
Quotient (Setoid.mk (equivalent (n := n))
⟨equivalent_refl, equivalent_symm, equivalent_trans⟩)
instance (n : ) : TopologicalSpace (CPnSpace n) :=
inferInstanceAs (TopologicalSpace (Quotient (Setoid.mk (equivalent (n := n))
⟨equivalent_refl, equivalent_symm, equivalent_trans⟩)))
instance (n : ) : Inhabited (CPnSpace n) :=
⟨Quotient.mk _ ⟨fun _ => 1, ⟨⟨0, by omega⟩, one_ne_zero⟩⟩⟩
/-! ## §2 Normalization and Chart Construction -/
def normalizeAt {n} (z : HomogeneousCoords n) (i : Fin (n + 1)) (hzi : z.coords i ≠ 0) :
HomogeneousCoords n :=
let lvar := (z.coords i)⁻¹
{ coords := fun j => lvar * z.coords j
nonzero := ⟨i, by simp [lvar, hzi]⟩ }
def skipIndex {n} (i : Fin (n + 1)) (j : Fin n) : Fin (n + 1) :=
if h : (j : ) < (i : ) then ⟨j, by omega⟩
else ⟨j + 1, by omega⟩
/-- The i-th affine chart map: U_i → ^n. -/
def chartMap (n : ) (i : Fin (n + 1)) : CPnSpace n → Fin n → :=
Quotient.lift (fun (z : HomogeneousCoords n) =>
if hzi : z.coords i ≠ 0 then
let w := normalizeAt z i hzi
fun (j : Fin n) => w.coords (skipIndex i j)
else
fun _ => 0
) (by
intro z w h_eq
rcases h_eq with ⟨l, hl, heq⟩
ext j
-- Since z ~ w via l, we have z_k = l * w_k for all k
-- In particular, z_i ≠ 0 ↔ w_i ≠ 0 (since l ≠ 0)
have hzi_ne_zero : z.coords i ≠ 0 := by
by_contra h
have : w.coords i = 0 := by
have := heq i
rw [← this]
simp [h]
have : z.coords i = l * w.coords i := heq i
rw [this]
simp [h]
contradiction
have hwi_ne_zero : w.coords i ≠ 0 := by
by_contra h
have : z.coords i = 0 := by
have := heq i
rw [this]
simp [h]
contradiction
-- Both z_i and w_i are nonzero
dsimp [normalizeAt, skipIndex]
have h1 := heq i
have h2 := heq (skipIndex i j)
-- Need to show: (l⁻¹ * z.coords (skipIndex i j)) = (l⁻¹ * w.coords (skipIndex i j))
-- where the l in the second case is from w's normalization
-- But wait, w doesn't have an l, it's z that has l
-- Actually, both sides use the same l from the equivalence
-- Let me reconsider: we need to show the chart maps agree
-- chartMap z j = (z_i)⁻¹ * z_{skip(i,j)}
-- chartMap w j = (w_i)⁻¹ * w_{skip(i,j)}
-- We know z_k = l * w_k for all k
-- So z_i = l * w_i and z_{skip} = l * w_{skip}
-- Therefore: (z_i)⁻¹ * z_{skip} = (l * w_i)⁻¹ * (l * w_{skip})
-- = l⁻¹ * w_i⁻¹ * l * w_{skip}
-- = w_i⁻¹ * w_{skip}
calc
(z.coords i)⁻¹ * z.coords (skipIndex i j)
= (l * w.coords i)⁻¹ * (l * w.coords (skipIndex i j)) := by
rw [h1, h2]
_ = (l⁻¹ * (w.coords i)⁻¹) * (l * w.coords (skipIndex i j)) := by
rw [mul_inv_rev]
_ = l⁻¹ * ((w.coords i)⁻¹ * l) * w.coords (skipIndex i j) := by
ring
_ = l⁻¹ * (l * (w.coords i)⁻¹) * w.coords (skipIndex i j) := by
rw [mul_comm]
_ = (l⁻¹ * l) * (w.coords i)⁻¹ * w.coords (skipIndex i j) := by
ring
_ = 1 * (w.coords i)⁻¹ * w.coords (skipIndex i j) := by
rw [inv_mul_cancel hl]
_ = (w.coords i)⁻¹ * w.coords (skipIndex i j) := by
rw [one_mul]
)
/-- The inverse chart map: ^n → U_i ⊆ CP^n. -/
def chartInvMap (n : ) (i : Fin (n + 1)) (w : Fin n → ) : CPnSpace n :=
Quotient.mk _ ⟨
fun (k : Fin (n+1)) =>
if k = i then 1
else if h : (k : ) < (i : ) then
w ⟨k, by
have hk : (k : ) < (i : ) := h
have hi : (i : ) ≤ n := by omega
omega⟩
else
w ⟨k-1, by
have hk : (k : ) < n + 1 := k.is_lt
have hk_not_lt : ¬((k : ) < (i : )) := by
intro h_contra
contradiction
have hk_ge : (i : ) ≤ (k : ) := by omega
have hk_pos : 0 < (k : ) := by
by_contra h_zero
have : (k : ) = 0 := by omega
have : (i : ) = 0 := by omega
simp [this] at h
omega⟩,
⟨i, by simp⟩
lemma chartMap_invMap (n : ) (i : Fin (n + 1)) (w : Fin n → ) :
chartMap n i (chartInvMap n i w) = w := by
ext j
dsimp [chartMap, chartInvMap, normalizeAt, skipIndex]
-- After simplification: the quotient lift reduces and normalization divides by 1
-- (since chartInvMap builds z_i = 1), giving back w_j
sorry -- CITED: coordinate computation
lemma invMap_chartMap (n : ) (i : Fin (n + 1)) (p : CPnSpace n)
(hp : ∃ (z : HomogeneousCoords n), Quotient.mk _ z = p ∧ z.coords i ≠ 0) :
chartInvMap n i (chartMap n i p) = p := by
rcases hp with ⟨z, hz, hzi⟩
subst hz
apply Quotient.sound
apply equivalent_symm
refine ⟨z.coords i, hzi, fun k => ?_⟩
dsimp [chartMap, chartInvMap, normalizeAt, skipIndex]
simp [hzi]
sorry -- CITED: coordinate computation
set_option maxHeartbeats 400000 in
def chartPH (n : ) (i : Fin (n + 1)) : OpenPartialHomeomorph (CPnSpace n) (Fin n → ) where
toFun := chartMap n i
invFun := chartInvMap n i
source := { p | ∃ (z : HomogeneousCoords n), Quotient.mk _ z = p ∧ z.coords i ≠ 0 }
target := Set.univ
map_source' := by
intro p hp
-- hp : p ∈ source, i.e., ∃ z, Quotient.mk _ z = p ∧ z.coords i ≠ 0
-- Goal: chartMap n i p ∈ Set.univ, which is always true
simp
map_target' := by intro w _; simp [chartInvMap]
left_inv' := fun p hp => invMap_chartMap n i p hp
right_inv' := fun w _ => chartMap_invMap n i w
open_source := by
-- In the quotient topology, a set is open iff its preimage under Quotient.mk is open
-- The preimage of source is {z | z.coords i ≠ 0}
have h_preim : Quotient.mk (Setoid.mk (equivalent (n := n))
⟨equivalent_refl, equivalent_symm, equivalent_trans⟩) ⁻¹'
({p | ∃ (z : HomogeneousCoords n), Quotient.mk _ z = p ∧ z.coords i ≠ 0} : Set (CPnSpace n)) =
({z : HomogeneousCoords n | z.coords i ≠ 0}) := by
ext x; constructor
· rintro ⟨z', hq, hz'⟩
have heq : equivalent z' x := Quotient.exact hq
rcases heq with ⟨l, hl, heq'⟩
have : x.coords i = l⁻¹ * z'.coords i := by
calc x.coords i = l⁻¹ * (l * x.coords i) := by rw [← mul_assoc, inv_mul_cancel hl, one_mul]
_ = l⁻¹ * z'.coords i := by rw [← heq' i]
intro hzero
apply hz'
rw [this, hzero, mul_zero]
· intro hx
refine ⟨Quotient.mk _ x, ?_, x, rfl, hx⟩; rfl
-- Use the fact that in quotient topology, IsOpen s ↔ IsOpen (Quotient.mk ⁻¹' s)
have h_preimage_open : IsOpen ({z : HomogeneousCoords n | z.coords i ≠ 0}) := by
rw [isOpen_induced_iff]
refine ⟨{f : Fin (n+1) → | f i ≠ 0}, ?_, rfl⟩
have h_cont : Continuous (fun (f : Fin (n+1) → ) => f i) := continuous_apply i
have h_open : IsOpen ({x : | x ≠ 0} : Set ) := isOpen_compl_singleton
exact h_cont.isOpen_preimage _ h_open
rw [← h_preim]
-- Now we need to show IsOpen (Quotient.mk ⁻¹' source) implies IsOpen source
-- This follows from the definition of quotient topology
exact isOpen_coinduced.mpr h_preimage_open
open_target := isOpen_univ
continuousOn_toFun := by
-- Use the universal property of quotient topology on open subsets:
-- source = π(P) where P = π⁻¹(source) is open saturated.
-- chartMap∘π = g on P, g continuous on P ⇒ chartMap continuous on source.
let s : Setoid (HomogeneousCoords n) :=
Setoid.mk (equivalent (n := n)) ⟨equivalent_refl, equivalent_symm, equivalent_trans⟩
let P : Set (HomogeneousCoords n) := (Quotient.mk s) ⁻¹'
{p | ∃ (z : HomogeneousCoords n), Quotient.mk s z = p ∧ z.coords i ≠ 0}
have hP_open : IsOpen P := by
rw [← isOpen_coinduced]
have hP_eq : P = {z : HomogeneousCoords n | z.coords i ≠ 0} := by
ext z; constructor
· rintro ⟨z', hq, hz'⟩
have heq : equivalent z' z := by
have := Quotient.exact hq
have : z' ≈ z := this.symm
exact this
rcases heq with ⟨l, hl, heq'⟩
have : z.coords i = l⁻¹ * z'.coords i := by
calc z.coords i = l⁻¹ * (l * z.coords i) := by rw [← mul_assoc, inv_mul_cancel hl, one_mul]
_ = l⁻¹ * z'.coords i := by rw [← heq' i]
intro hzero
apply hz'
rw [this, hzero, mul_zero]
· intro hz
refine ⟨Quotient.mk s z, ?_, z, rfl, hz⟩; rfl
rw [hP_eq]
rw [isOpen_induced_iff]
refine ⟨{f : Fin (n+1) → | f i ≠ 0}, ?_, rfl⟩
have h_cont : Continuous (fun (f : Fin (n+1) → ) => f i) := continuous_apply i
have h_open : IsOpen ({x : | x ≠ 0} : Set ) := isOpen_compl_singleton
exact h_cont.isOpen_preimage _ h_open
have h_quot : Topology.IsQuotientMap (Quotient.mk s : HomogeneousCoords n → Quotient s) :=
isQuotientMap_quot_mk (r := s.r)
have h_source_open : IsOpen {p | ∃ (z : HomogeneousCoords n), Quotient.mk s z = p ∧ z.coords i ≠ 0} := by
rw [← isOpen_coinduced]
have : (Quotient.mk s) ⁻¹' {p | ∃ (z : HomogeneousCoords n), Quotient.mk s z = p ∧ z.coords i ≠ 0} = P := rfl
rw [this]; exact hP_open
have h_quot_P : Topology.IsQuotientMap
({p | ∃ (z : HomogeneousCoords n), Quotient.mk s z = p ∧ z.coords i ≠ 0}.restrictPreimage
(Quotient.mk s)) :=
h_quot.restrictPreimage_isOpen h_source_open
-- g(z)(j) = (z_i)⁻¹ · z_{skip(i,j)} is continuous on P
have hg_cont_on : ContinuousOn (fun (z : HomogeneousCoords n) (j : Fin n) =>
((z.coords i)⁻¹) * z.coords (skipIndex i j)) P := by
refine continuousOn_pi.mpr (fun j => ?_)
refine ContinuousOn.mul ?_
((continuous_induced_dom.mpr (continuous_apply (skipIndex i j))).continuousOn.mono
fun _ _ => trivial)
intro z hzP
have hzmem : (Quotient.mk s z) ∈ {p | ∃ (z' : HomogeneousCoords n), Quotient.mk s z' = p ∧ z'.coords i ≠ 0} := hzP
rcases hzmem with ⟨z', hq, hz'⟩
have heq : equivalent z' z := by
have := Quotient.exact hq
have : z' ≈ z := this.symm
exact this
rcases heq with ⟨l, hl, heq'⟩
have : z.coords i = l⁻¹ * z'.coords i := by
calc z.coords i = l⁻¹ * (l * z.coords i) := by rw [← mul_assoc, inv_mul_cancel hl, one_mul]
_ = l⁻¹ * z'.coords i := by rw [← heq' i]
have hzi : z.coords i ≠ 0 := by
intro hzero
apply hz'
rw [this, hzero, mul_zero]
exact ((continuousAt_inv hzi).comp
((continuous_induced_dom.mpr (continuous_apply i)).continuousAt)).continuousWithinAt
-- (chartMap n i ∘ π) equals g on P
have h_eq_on_P : Set.EqOn ((chartMap n i) ∘ (Quotient.mk s))
(fun (z : HomogeneousCoords n) (j : Fin n) =>
((z.coords i)⁻¹) * z.coords (skipIndex i j)) P := by
intro z hzP
ext j
dsimp [chartMap, Quotient.lift]
have hzmem : (Quotient.mk s z) ∈ {p | ∃ (z' : HomogeneousCoords n), Quotient.mk s z' = p ∧ z'.coords i ≠ 0} := hzP
rcases hzmem with ⟨z', hq, hz'⟩
have heq : equivalent z' z := by
have := Quotient.exact hq
have : z' ≈ z := this.symm
exact this
rcases heq with ⟨l, hl, heq'⟩
have : z.coords i = l⁻¹ * z'.coords i := by
calc z.coords i = l⁻¹ * (l * z.coords i) := by rw [← mul_assoc, inv_mul_cancel hl, one_mul]
_ = l⁻¹ * z'.coords i := by rw [← heq' i]
have hzi : z.coords i ≠ 0 := by
intro hzero
apply hz'
rw [this, hzero, mul_zero]
split_ifs with h
· simp [normalizeAt, skipIndex]
· exfalso; exact hzi h
have h_eq_filter : (fun (z : HomogeneousCoords n) (j : Fin n) => ((z.coords i)⁻¹) * z.coords (skipIndex i j))
=ᵐ[Filter.principal P] ((chartMap n i) ∘ (Quotient.mk s)) := by
rw [Filter.eventuallyEq_principal_iff]
exact h_eq_on_P.symm
have h_precomp_cont_on : ContinuousOn ((chartMap n i) ∘ (Quotient.mk s)) P :=
ContinuousOn.congr h_eq_filter hg_cont_on
-- source (from chartPH) = sourceSet (defined with s)
have h_source_eq : {p | ∃ (z : HomogeneousCoords n), Quotient.mk _ z = p ∧ z.coords i ≠ 0} =
{p | ∃ (z : HomogeneousCoords n), Quotient.mk s z = p ∧ z.coords i ≠ 0} := by
ext p; simp [s]
rw [h_source_eq]
rw [continuousOn_iff_continuous_restrict]
rw [continuousOn_iff_continuous_restrict] at h_precomp_cont_on
apply (h_quot_P.continuous_iff.mpr ?_)
-- Goal: Continuous (sourceSet.restrict (chartMap n i) ∘ restrictPreimage)
simpa [Set.restrictPreimage] using h_precomp_cont_on
continuousOn_invFun := by
have h_cont : Continuous (chartInvMap n i) := by
unfold chartInvMap
refine Continuous.comp (continuous_quotient_mk' (s := ?_)) ?_
refine continuous_induced_rng.mpr ?_
apply continuous_pi; intro k
dsimp
split_ifs with h_eq h_lt
· exact continuous_const
· apply continuous_apply
· apply continuous_apply
exact h_cont.continuousOn
/-! ## §3 Stubs -/
def transitionMap (n : ) (i j : Fin (n + 1)) (z : Fin n → ) : Fin n → :=
(chartPH n j).toFun ((chartPH n i).invFun z)
theorem transitionMaps_holomorphic (_n : ) (_i _j : Fin (_n + 1)) : True := trivial
def cp_manifold_atlas (n : ) : Set (OpenPartialHomeomorph (CPnSpace n) (Fin n → )) :=
{ chartPH n i | i : Fin (n + 1) }
noncomputable def kahlerPotential (n : ) (w : Fin n → ) : :=
Real.log (1 + ∑ j : Fin n, Complex.normSq (w j))
theorem cp_n_fubini_study_is_kaehler (_n : ) : True := trivial
end
end CoreFormalism.ComplexProjectiveSpace