English

Symmetric Exponential Time Requires Near-Maximum Circuit Size

Computational Complexity 2023-09-25 v1

Abstract

We show that there is a language in S2E/1\mathsf{S}_2\mathsf{E}/_1 (symmetric exponential time with one bit of advice) with circuit complexity at least 2n/n2^n/n. In particular, the above also implies the same near-maximum circuit lower bounds for the classes Σ2E\Sigma_2\mathsf{E}, (Σ2EΠ2E)/1(\Sigma_2\mathsf{E}\cap\Pi_2\mathsf{E})/_1, and ZPENP/1\mathsf{ZPE}^{\mathsf{NP}}/_1. Previously, only "half-exponential" circuit lower bounds for these complexity classes were known, and the smallest complexity class known to require exponential circuit complexity was Δ3E=EΣ2P\Delta_3\mathsf{E} = \mathsf{E}^{\Sigma_2\mathsf{P}} (Miltersen, Vinodchandran, and Watanabe COCOON'99). Our circuit lower bounds are corollaries of an unconditional zero-error pseudodeterministic algorithm with an NP\mathsf{NP} oracle and one bit of advice (FZPPNP/1\mathsf{FZPP}^{\mathsf{NP}}/_1) that solves the range avoidance problem infinitely often. This algorithm also implies unconditional infinitely-often pseudodeterministic FZPPNP/1\mathsf{FZPP}^{\mathsf{NP}}/_1 constructions for Ramsey graphs, rigid matrices, two-source extractors, linear codes, and Kpoly\mathrm{K}^{\mathrm{poly}}-random strings with nearly optimal parameters. Our proofs relativize. The two main technical ingredients are (1) Korten's PNP\mathsf{P}^{\mathsf{NP}} reduction from the range avoidance problem to constructing hard truth tables (FOCS'21), which was in turn inspired by a result of Je\v{r}\'abek on provability in Bounded Arithmetic (Ann. Pure Appl. Log. 2004); and (2) the recent iterative win-win paradigm of Chen, Lu, Oliveira, Ren, and Santhanam (FOCS'23).

Keywords

Cite

@article{arxiv.2309.12912,
  title  = {Symmetric Exponential Time Requires Near-Maximum Circuit Size},
  author = {Lijie Chen and Shuichi Hirahara and Hanlin Ren},
  journal= {arXiv preprint arXiv:2309.12912},
  year   = {2023}
}
R2 v1 2026-06-28T12:29:31.943Z