When Relaxation Does Not Help: RLDCs with Small Soundness Yield LDCs

This paper demonstrates that any non-adaptive qq-query relaxed locally decodable code (RLDC) with sufficiently small soundness error can be converted into a standard qq-query locally decodable code (LDC) with comparable parameters, thereby generalizing previous separation results and yielding improved lower bounds for RLDCs, relaxed locally correctable codes (RLCCs), and probabilistically checkable proofs of proximity (PCPPs).

Kuan Cheng, Xin Li, Songtao Mao2026-03-05🔢 math