Scheme-Theoretic Approach to Computational Complexity. III. SETH
Ali Çivril
TL;DR
The paper proves a SETH-style deterministic lower bound for solving $k$-SAT with $k \ge 3$ by constructing a prime homogeneous simple sub-problem that encodes a large number of instances. It then mixes blocks to enforce primeness while preserving the Hilbert-polynomial structure, enabling a counting argument. A Hilbert-polynomial and Stirling-based analysis yields a lower bound of $\tau(k\text{-SAT}(n)) \ge (2^{k-\frac{3}{2}-\epsilon})^{\frac{n}{k+1}}$ for infinitely many $n$ and any $\epsilon>0$, with $n$ the number of variables. This strengthens unconditional hardness results for exact $k$-SAT under SETH and links algebraic considerations to deterministic time complexity.
Abstract
We show that there exist infinitely many $n \in \mathbb{Z}^+$ such that for any constant $ε> 0$, any deterministic algorithm to solve $k$-\textsf{SAT} for $k \geq 3$ must perform at least $(2^{k-\frac{3}{2}-ε})^{\frac{n}{k+1}}$ operations, where $n$ is the number of variables in the $k$\textsf{-SAT} instance.
