BQP, meet NP: Search-to-decision reductions and approximate counting

التفاصيل البيبلوغرافية
العنوان: BQP, meet NP: Search-to-decision reductions and approximate counting
المؤلفون: Gharibian, Sevag, Kamminga, Jonas
المصدر: 51st International Colloquium on Automata, Languages, and Programming (ICALP 2024), Volume 297, pp. 70:1-70:19
سنة النشر: 2024
المجموعة: Computer Science
Quantum Physics
مصطلحات موضوعية: Quantum Physics, Computer Science - Computational Complexity
الوصف: What is the power of polynomial-time quantum computation with access to an NP oracle? In this work, we focus on two fundamental tasks from the study of Boolean satisfiability (SAT) problems: search-to-decision reductions, and approximate counting. We first show that, in strong contrast to the classical setting where a poly-time Turing machine requires $\Theta(n)$ queries to an NP oracle to compute a witness to a given SAT formula, quantumly $\Theta(\log n)$ queries suffice. We then show this is tight in the black-box model - any quantum algorithm with "NP-like" query access to a formula requires $\Omega(\log n)$ queries to extract a solution with constant probability. Moving to approximate counting of SAT solutions, by exploiting a quantum link between search-to-decision reductions and approximate counting, we show that existing classical approximate counting algorithms are likely optimal. First, we give a lower bound in the "NP-like" black-box query setting: Approximate counting requires $\Omega(\log n)$ queries, even on a quantum computer. We then give a "white-box" lower bound (i.e. where the input formula is not hidden in the oracle) - if there exists a randomized poly-time classical or quantum algorithm for approximate counting making $o(log n)$ NP queries, then $\text{BPP}^{\text{NP}[o(n)]}$ contains a $\text{P}^{\text{NP}}$-complete problem if the algorithm is classical and $\text{FBQP}^{\text{NP}[o(n)]}$ contains an $\text{FP}^{\text{NP}}$-complete problem if the algorithm is quantum.
نوع الوثيقة: Working Paper
DOI: 10.4230/LIPIcs.ICALP.2024.70
URL الوصول: http://arxiv.org/abs/2401.03943
رقم الأكسشن: edsarx.2401.03943
قاعدة البيانات: arXiv
الوصف
DOI:10.4230/LIPIcs.ICALP.2024.70