A Brief Note on a Recent Claim About NP-Hard Problems and BQP
Michael C. Chavrimootoo
TL;DR
The paper targets the question of whether NP-hard problems can lie in $BQP$ and critiques Czerwinski's claim that no NP-hard set is in $BQP$. It analyzes the main argument and identifies three flaws—one major and two minor—that undermine the purported proof, including a misdefinition of foundational sets and a misinterpretation of a key theorem. The major flaw hinges on a noncomputability assertion that, in fact, corresponds to an exponential-time computable process, invalidating the central claim. Consequently, the purported consequences such as ${ m NP}\not\subseteq {\rm BQP}$ or ${\rm P} \neq {\rm NP}$ do not follow from Czerwinski's work, and the note clarifies why the claimed separation remains unestablished by that paper.
Abstract
This short note outlines some of the issues in Czerwinski's paper [Cze23] claiming that NP-hard problems are not in BQP. We outline one major issue and two minor issues, and conclude that their paper does not establish what they claim it does.
