,
Yichuan Wang
Creative Commons Attribution 4.0 International license
Whether BPL = 𝖫 (which is conjectured to be equal) or even whether BPL ⊆ NL, is a big open problem in theoretical computer science. It is well known that 𝖫 ⊆ NL ⊆ L-AC¹. In this work we show that BPL ⊆ L-AC¹ also holds. Our proof is based on a new iteration method for boosting precision in approximating matrix powering, which is inspired by the Richardson Iteration method developed in a recent line of work [AmirMahdi Ahmadinejad et al., 2020; Edward Pyne and Salil P. Vadhan, 2021; Gil Cohen et al., 2021; William M. Hoza, 2021; Gil Cohen et al., 2023; Aaron (Louie) Putterman and Edward Pyne, 2023; Lijie Chen et al., 2023]. We also improve the algorithm for approximate counting in low-depth L-AC circuits from an additive error setting to a multiplicative error setting.
@InProceedings{cheng_et_al:LIPIcs.CCC.2024.32,
author = {Cheng, Kuan and Wang, Yichuan},
title = {{BPL ⊆ L-AC¹}},
booktitle = {39th Computational Complexity Conference (CCC 2024)},
pages = {32:1--32:14},
series = {Leibniz International Proceedings in Informatics (LIPIcs)},
ISBN = {978-3-95977-331-7},
ISSN = {1868-8969},
year = {2024},
volume = {300},
editor = {Santhanam, Rahul},
publisher = {Schloss Dagstuhl -- Leibniz-Zentrum f{\"u}r Informatik},
address = {Dagstuhl, Germany},
URL = {https://drops.dagstuhl.de/entities/document/10.4230/LIPIcs.CCC.2024.32},
URN = {urn:nbn:de:0030-drops-204282},
doi = {10.4230/LIPIcs.CCC.2024.32},
annote = {Keywords: Randomized Space Complexity, Circuit Complexity, Derandomization}
}