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DerivedAlgGeo.CategoryTheory.Triangulated.StabilityCondition.CentralCharge.Quadratic

Quadratic-space interpretations of paired complex functionals #

LinearAlgebra/QuadraticForm/ComplexPairing.lean owns the functional and its kernel algebra. This file is the downstream adapter that interprets kernel vanishing against the orthogonality loci attached to positive frames.

Kernel negativity alone is not called the quadratic support property here. The full predicate in Weak/Support/Predicate/Quadratic.lean also requires the same quadratic form to be nonnegative on the selected semistable classes. No determinant alignment or destabilization claim is made here.

A class is orthogonal to the plane underlying a positive frame exactly when its paired complex functional vanishes.

theorem PeriodDomain.mem_positivePlanesAway_iff_centralCharge_ne_zero {M : Type u_1} [AddCommGroup M] [Module ℝ M] {Q : QuadraticForm ℝ M} {x y : M} (hxy : IsPositiveFrame Q x y) (Δ : Set M) :
framePlane (x, y) ∈ positivePlanesAway Q Δ ↔ ∀ δ ∈ Δ, centralCharge Q x y δ ≠ 0

A positive frame maps into the deleted-locus complement exactly when its paired complex functional kills no member of the cutting set.

theorem Mukai.mem_orthogonalityLocus_iff_expCharge_eq_zero {V : Type u_1} [AddCommGroup V] [Module ℝ V] (b : V →ₗ[ℝ] V →ₗ[ℝ] ℝ) (β ω : V) (hb : ∀ (x y : V), (b x) y = (b y) x) (hω : 0 < (b ω) ω) {δ : RealExtension V} :

A spherical orthogonality locus for the exponential pair is the vanishing locus of its additive exponential charge.

theorem Mukai.mem_positivePlanesAway_iff_expCharge_ne_zero {V : Type u_1} [AddCommGroup V] [Module ℝ V] (b : V →ₗ[ℝ] V →ₗ[ℝ] ℝ) (β ω : V) (hb : ∀ (x y : V), (b x) y = (b y) x) (hω : 0 < (b ω) ω) (Δ : Set (RealExtension V)) :

The cut exponential period domain is the locus where the charge kills no class in Δ.