ECCC-Report TR19-080https://eccc.weizmann.ac.il/report/2019/080Comments and Revisions published for TR19-080en-usSat, 01 Jun 2019 19:43:20 +0300
Paper TR19-080
| On List Recovery of High-Rate Tensor Codes |
Noga Ron-Zewi,
Swastik Kopparty,
Shubhangi Saraf,
Nicolas Resch,
Shashwat Silas
https://eccc.weizmann.ac.il/report/2019/080We continue the study of list recovery properties of high-rate tensor codes, initiated by Hemenway, Ron-Zewi, and Wootters (FOCS'17). In that work it was shown that the tensor product of an efficient (poly-time) high-rate globally list recoverable code is {\em approximately} locally list recoverable, as well as globally list recoverable in {\em probabilistic} near-linear time. This was used in turn to give the first capacity-achieving list decodable codes with (1) local list decoding algorithms, and with (2) {\em probabilistic} near-linear time global list decoding algorithms. This was also yielded constant-rate codes approaching the Gilbert-Varshamov bound with {\em probabilistic} near-linear time global unique decoding algorithms.
In the current work we obtain the following results:
1. The tensor product of an efficient (poly-time) high-rate globally list recoverable code is globally list recoverable in {\em deterministic} near-linear time. This yields in turn the first capacity-achieving list decodable codes with {\em deterministic} near-linear time global list decoding algorithms. It also gives constant-rate codes approaching the Gilbert Varshamov bound with {\em deterministic} near-linear time global unique decoding algorithms.
2. If the base code is additionally locally correctable, then the tensor product is (genuinely) locally list recoverable. This yields in turn constant-rate codes approaching the Gilbert-Varshamov bound that are {\em locally correctable} with query complexity and running time $N^{o(1)}$. This improves over prior work by Gopi et. al. (SODA'17; IEEE Transactions on Information Theory'18) that only gave query complexity $N^{\epsilon}$ with rate that is exponentially small in $1/\epsilon$.
3. A nearly-tight combinatorial lower bound on output list size for list recovering high-rate tensor codes. This bound implies in turn a nearly-tight lower bound of $N^{\Omega(1/\log \log N)}$ on the product of query complexity and output list size for locally list recovering high-rate tensor codes.Sat, 01 Jun 2019 19:43:20 +0300https://eccc.weizmann.ac.il/report/2019/080