Generalized Samorodnitsky noisy function inequalities, with applications to error-correcting codes

Fuente: arXiv
Guardado en:
Detalles Bibliográficos
Autores principales: Abawonse, Olakunle S., Hazla, Jan, O'Donnell, Ryan
Formato: Preprint
Publicado: 2025
Materias:
Acceso en línea:
Etiquetas: Agregar Etiqueta
Sin Etiquetas, Sea el primero en etiquetar este registro!
_version_ 1866908483652157440
author Abawonse, Olakunle S.
Hazla, Jan
O'Donnell, Ryan
author_facet Abawonse, Olakunle S.
Hazla, Jan
O'Donnell, Ryan
contents An inequality by Samorodnitsky states that if $f : \mathbb{F}_2^n \to \mathbb{R}$ is a nonnegative boolean function, and $S \subseteq [n]$ is chosen by randomly including each coordinate with probability a certain $λ= λ(q,ρ) < 1$, then \begin{equation} \log \|T_ρf\|_q \leq \mathbb{E}_{S} \log \|\mathbb{E}(f|S)\|_q\;. \end{equation} Samorodnitsky's inequality has several applications to the theory of error-correcting codes. Perhaps most notably, it can be used to show that \emph{any} binary linear code (with minimum distance $ω(\log n)$) that has vanishing decoding error probability on the BEC$(λ)$ (binary erasure channel) also has vanishing decoding error on \emph{all} memoryless symmetric channels with capacity above some $C = C(λ)$. Samorodnitsky determined the optimal $λ= λ(q,ρ)$ for his inequality in the case that $q \geq 2$ is an integer. In this work, we generalize the inequality to $f : Ω^n \to \mathbb{R}$ under any product probability distribution $μ^{\otimes n}$ on $Ω^n$; moreover, we determine the optimal value of $λ= λ(q,μ,ρ)$ for any real $q \in [2,\infty]$, $ρ\in [0,1]$, and distribution~$μ$. As one consequence, we obtain the aforementioned coding theory result for linear codes over \emph{any} finite alphabet.
format Preprint
id arxiv_https___arxiv_org_abs_2508_06940
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Generalized Samorodnitsky noisy function inequalities, with applications to error-correcting codes
Abawonse, Olakunle S.
Hazla, Jan
O'Donnell, Ryan
Information Theory
68P30 (Primary) 68Q30, 94B70 (Secondary)
An inequality by Samorodnitsky states that if $f : \mathbb{F}_2^n \to \mathbb{R}$ is a nonnegative boolean function, and $S \subseteq [n]$ is chosen by randomly including each coordinate with probability a certain $λ= λ(q,ρ) < 1$, then \begin{equation} \log \|T_ρf\|_q \leq \mathbb{E}_{S} \log \|\mathbb{E}(f|S)\|_q\;. \end{equation} Samorodnitsky's inequality has several applications to the theory of error-correcting codes. Perhaps most notably, it can be used to show that \emph{any} binary linear code (with minimum distance $ω(\log n)$) that has vanishing decoding error probability on the BEC$(λ)$ (binary erasure channel) also has vanishing decoding error on \emph{all} memoryless symmetric channels with capacity above some $C = C(λ)$. Samorodnitsky determined the optimal $λ= λ(q,ρ)$ for his inequality in the case that $q \geq 2$ is an integer. In this work, we generalize the inequality to $f : Ω^n \to \mathbb{R}$ under any product probability distribution $μ^{\otimes n}$ on $Ω^n$; moreover, we determine the optimal value of $λ= λ(q,μ,ρ)$ for any real $q \in [2,\infty]$, $ρ\in [0,1]$, and distribution~$μ$. As one consequence, we obtain the aforementioned coding theory result for linear codes over \emph{any} finite alphabet.
title Generalized Samorodnitsky noisy function inequalities, with applications to error-correcting codes
topic Information Theory
68P30 (Primary) 68Q30, 94B70 (Secondary)
url https://arxiv.org/abs/2508.06940