This research derives exact contraction coefficients for Jensen–Shannon and χ² divergences in a binary Z-channel, suggesting important implications for information processing.
We derive exact strong data-processing (contraction) coefficients for the Jensen–Shannon and χ² divergences under the binary Z-channel with parameter ε∈[0,1]. Using fully analytic arguments, we prove that both coefficients coincide and equal 1−ε. The proofs rely on closed-form optimization for χ² and a sharp monotonicity argument for JSD; figures are included for intuition only.
No takes yet. Share an insight, caveat, or question.
Alex B. Shvets (2026) studied this question.
Synapse has enriched 5 closely related papers on similar clinical questions. Consider them for comparative context: