Jensen-Shannon Divergence Contraction Coefficients for m-ary Symmetric Channels: Exact Formulas and Strictness Results
Abstract
Jensen-Shannon Divergence Contraction Coefficients for m-ary Symmetric Channels. Main result: η_JSD = λ²_m / s_m where λ_m = 1 - mδ/(m-1) and s_m = 1 - (m-2)δ/(m-1). Key contributions:- Exact closed-form formula for m-ary symmetric channels- Binary Uniqueness Theorem: η_JSD = η_χ² iff m = 2- For m ≥ 3: η_JSD > η_χ² (JSD is more conservative) v7 changes:- Full proof in Appendix A (3 pages, 4 lemmas + 2 propositions)- Corrected Nishiyama-Sason reference (source-channel vs channel coefficient)- 6 figures added- 9 pages total
Fields of Study & Subjects
Advanced Harmonic Analysis Research
Wireless Communication Security Techniques
Random Matrices and Applications
Publication details
- Journal / source
- Zenodo (CERN European Organization for Nuclear Research)
- Publication date
- 8 January 2026
- Language
- EN
- Document type
- Preprint