Cutoff sequences #
Improper integrals as cutoff limits #
For f integrable on (0, ∞), the interval integrals over [αₙ, Tₙ] converge to the
integral over (0, ∞).
Positivity of operator-valued integrals #
A set integral of a positive integrand over a set of finite measure is positive.
The Gram kernel #
The resolver Gram kernel ∫₀^∞ F(F+u)⁻¹ G(G+u)⁻¹ du.
Equations
- CommutingRepetition.Resolver.kern F G = ∫ (u : ℝ) in Set.Ioi 0, CommutingRepetition.Resolver.fib F u * CommutingRepetition.Resolver.fib G u
Instances For
Integrability of the kernel integrand on (0, ∞): bounded by 1 near 0 and by
‖F‖ ‖G‖ / u² at infinity.
The cutoff integrals converge to the kernel.
K(F, F) = F.
K(F, G)* = K(G, F).
The kernel entropy inequality #
The entropic correction converges to −negMulLog(F) along the cutoffs.
Continuity on [αₙ, Tₙ] of the weighted difference-square integrand.
Continuity on [αₙ, Tₙ] of the weighted resolvent integrand.
The integrated pointwise bound (node 1.2.6.2 over [αₙ, Tₙ]).
Evaluation of the right side: ∑ wᵢ hfun(Fᵢ) − W hfun(F̄).
Evaluation of the left side as a combination of cutoff kernel integrals.
Algebra of the right side: the constant and linear parts cancel by ∑ wᵢ Fᵢ = W F̄.
Kernel entropy inequality.
Membership of the kernel in closed star subalgebras #
The kernel of two elements of a closed star subalgebra lies in it.