Lower Bounds for Adaptive Relaxed Locally Decodable Codes via the Capped Horvitz--Thompson Estimator
Abstract
We prove a nearly optimal lower bound on the blocklength of general relaxed locally decodable codes (RLDCs), extending the result of [GGS26] to nonlinear encodings and adaptive decoders with two-sided error. Namely, we show that any q-query RLDC C: {0,1}k → {0,1}n must satisfy n = k1+Ω(1/q), closely matching the upper bound of n = k1+O(1/q) by Ben-Sasson, Goldreich, Harsha, Sudan, and Vadhan (STOC 2004). Our proof reduces showing RLDC lower bounds to estimating the output distribution of adaptive decoders. To this end, we introduce a capped Horvitz--Thompson estimator with uniformly bounded discrete derivatives on the p-biased cube. We establish its concentration of measure via self-bounding inequalities and control the downward bias induced by capping through a spreadness argument.
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BibTeX
@misc{goldberg2026lower,
title = {{Lower Bounds for Adaptive Relaxed Locally Decodable Codes via the Capped Horvitz--Thompson Estimator}},
author = {Guy Goldberg and Tom Gur and Sidhant Saraogi},
howpublished = {arXiv},
year = {2026},
month = nov,
doi = {10.48550/arxiv.2611.04678},
eprint = {2611.04678},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2611.04678},
note = {CC BY 4.0},
}
RIS
TY - UNPB
TI - Lower Bounds for Adaptive Relaxed Locally Decodable Codes via the Capped Horvitz--Thompson Estimator
AU - Guy Goldberg
AU - Tom Gur
AU - Sidhant Saraogi
PY - 2026
DA - 2026/11/03
PB - arXiv
DO - 10.48550/arxiv.2611.04678
UR - https://arxiv.org/abs/2611.04678
AB - We prove a nearly optimal lower bound on the blocklength of general relaxed locally decodable codes (RLDCs), extending the result of [GGS26] to nonlinear encodings and adaptive decoders with two-sided error. Namely, we show that any q-query RLDC C: {0,1}^k → {0,1}^n must satisfy n = k^1+Ω(1/q), closely matching the upper bound of n = k^1+O(1/q) by Ben-Sasson, Goldreich, Harsha, Sudan, and Vadhan (STOC 2004). Our proof reduces showing RLDC lower bounds to estimating the output distribution of adaptive decoders. To this end, we introduce a capped Horvitz--Thompson estimator with uniformly bounded discrete derivatives on the p-biased cube. We establish its concentration of measure via self-bounding inequalities and control the downward bias induced by capping through a spreadness argument.
ER -