Dimension growth for homogeneous prime ideals of positive projective dimension.
theorem
CCDN.projective_variety_dimension_growth
(m k : ℕ)
:
∃ (C : ℝ),
0 < C ∧ ∀ (I : Ideal (MvPolynomial (Fin (m + k + 2)) ℚ)),
I.IsPrime →
IsHomogeneousIdeal I →
∀ (d : ℕ),
5 ≤ d →
HasProjectiveDimensionDegree I (m + 1) d →
∀ (B : ℝ),
1 ≤ B →
↑(projectiveCount (projectiveIdealZeroLocus I) B) ≤ C * ↑d ^ projectionDegreeExponent m k * B ^ (m + 1)
The general projective-variety bound, with dimension and codimension displayed separately. The hypotheses use the Hilbert polynomial of the coordinate ring.