OAI/Geometry/EinsteinFour/Spectral.lean
2 declarations, 0 contain sorry, 0 declared as axioms
Spectral bounds for a Weyl block
Only the three real eigenvalues and their trace and norm identities are used.
The minimum eigenvalue is -x, and the Hilbert--Schmidt norm is sqrt 6 * v.
- theorem
OAI.PositiveEinsteinFour.weyl_eigenvalue_norm_boundsline 17Source documentation
The least eigenvalue of a real trace-free three-dimensional block controls its normalized norm, including the zero block. This is the bound
v ≤ x ≤ 2vfrom Section 2 of the manuscript.theorem weyl_eigenvalue_norm_bounds (v x s t : ℝ) (hv : 0 ≤ v) (htrace : -x + s + t = 0) (hnorm : x ^ 2 + s ^ 2 + t ^ 2 = 6 * v ^ 2) (hs : -x ≤ s) (ht : -x ≤ t) : v ≤ x ∧ x ≤ 2 * v := by … - theorem
OAI.PositiveEinsteinFour.weyl_norm_sum_lt_twoline 34Source documentation
Sectional positivity expressed by the two minimum eigenvalues implies the strict sum bound for the normalized Weyl norms.
theorem weyl_norm_sum_lt_two (v b x y : ℝ) (hvx : v ≤ x) (hby : b ≤ y) (hpositive : x + y < 2) : v + b < 2 := by …