Rewriting the primitive weight using visit probabilities #
This file records the exact algebraic bridge from the explicit visit-probability formula
v_x(n) = 1 / (B_x n log n) to the weighted series identity
f(A) = B_x * ∑_{n ∈ A} v_x(n), and packages the final deterministic reduction from a
summable hit series to the logarithmic-series bound.
Main statements #
theorem
PrimitiveSetsAboveX.summable_indicatorLogSeries_and_tsum_le_of_hitMass
{x Y : ℕ}
(chain : MarkovLayer x Y)
(hx : 2 ≤ x)
{A : Set ℕ}
(hA : A ⊆ Set.Ici x)
(hB : 0 < normalizationConstant x Y)
(hHitSummable : Summable (A.indicator chain.visitProbability))
(hHit : ∑' (n : ℕ), A.indicator chain.visitProbability n ≤ 1)
{C : ℝ}
(hNorm : |normalizationConstant x Y - 1| ≤ C / Real.log ↑x)
:
If the visit-probability series on A is summable and has total mass at most 1, then the
logarithmic series on A is summable as well, and the normalization estimate converts this into
the final upper bound for ∑_{n ∈ A} 1 / (n log n).