English
Related papers

Related papers: Quantum Merlin Arthur with Exponentially Small Gap

200 papers

We introduce a 2-round stochastic constraint-satisfaction problem, and show that its approximation version is complete for (the promise version of) the complexity class AM. This gives a `PCP characterization' of AM analogous to the PCP…

Computational Complexity · Computer Science 2010-02-22 Andrew Drucker

We extend the concept of polynomial time approximation algorithms to apply to problems for hierarchically specified graphs, many of which are PSPACE-complete. Assuming P != PSPACE, the existence or nonexistence of such efficient…

Combinatorics · Mathematics 2016-09-06 Madhav V. Marathe , Harry B. Hunt , S. S. Ravi

We find a modification to QMA where having one quantum proof is strictly less powerful than having two unentangled proofs, assuming EXP $\ne$ NEXP. This gives a new route to prove QMA(2) = NEXP that overcomes the primary drawback of a…

Quantum Physics · Physics 2024-10-28 Roozbeh Bassirian , Bill Fefferman , Itai Leigh , Kunal Marwaha , Pei Wu

Approximate message passing (AMP) is a family of iterative algorithms that generalize matrix power iteration. AMP algorithms are known to optimally solve many average-case optimization problems. In this paper, we show that a large class of…

Data Structures and Algorithms · Computer Science 2023-11-16 Misha Ivkov , Tselil Schramm

Quantum Boltzmann machines (QBMs) are machine-learning models for both classical and quantum data. We give an operational definition of QBM learning in terms of the difference in expectation values between the model and target, taking into…

Quantum Physics · Physics 2025-02-13 Luuk Coopmans , Marcello Benedetti

This paper considers the following problem. Two mixed-state quantum circuits Q and R are given, and the goal is to determine which of two possibilities holds: (i) Q and R act nearly identically on all possible quantum state inputs, or (ii)…

Computational Complexity · Computer Science 2007-05-23 Bill Rosgen , John Watrous

This paper presents an efficient parallel approximation scheme for a new class of min-max problems. The algorithm is derived from the matrix multiplicative weights update method and can be used to find near-optimal strategies for…

Quantum Physics · Physics 2015-03-17 Gus Gutoski , Xiaodi Wu

We consider the average-case complexity of some otherwise undecidable or open Diophantine problems. More precisely, we show that the following two problems can be solved in the complexity class PSPACE: (I) Given polynomials f_1,...,f_m in…

Number Theory · Mathematics 2007-05-23 J. Maurice Rojas

In recent work it is shown that Q-learning with linear function approximation is stable, in the sense of bounded parameter estimates, under the $(\varepsilon,\kappa)$-tamed Gibbs policy; $\kappa$ is inverse temperature, and $\varepsilon>0$…

Machine Learning · Computer Science 2026-02-09 Prashant Mehta , Sean Meyn

The potential of the exact quantum information processing is an interesting, important and intriguing issue. For examples, it has been believed that quantum tools can provide significant, that is larger than polynomial, advantages in the…

Formal Languages and Automata Theory · Computer Science 2014-11-26 Jozef Gruska , Daowen Qiu , Shenggen Zheng

We present a type system for an extension of lambda calculus with a conditional construction, named STAB, that characterizes the PSPACE class. This system is obtained by extending STA, a type assignment for lambda-calculus inspired by…

Logic in Computer Science · Computer Science 2010-06-02 Marco Gaboardi , Jean-Yves Marion , Simona Ronchi Della Rocca

We consider the state-minimisation problem for weighted and probabilistic automata. We provide a numerically stable polynomial-time minimisation algorithm for weighted automata, with guaranteed bounds on the numerical error when run with…

Formal Languages and Automata Theory · Computer Science 2014-05-02 Stefan Kiefer , Björn Wachter

Empirical Bayes methods are widely used for large-scale estimation and inference in the Poisson means problem. Existing results establish theoretical properties of the nonparametric maximum likelihood estimator (NPMLE) for optimal posterior…

Statistics Theory · Mathematics 2026-05-06 Taehyun Kim

The Metropolis process (MP) and Simulated Annealing (SA) are stochastic local search heuristics that are often used in solving combinatorial optimization problems. Despite significant interest, there are very few theoretical results…

Data Structures and Algorithms · Computer Science 2023-12-22 Zongchen Chen , Dan Mikulincer , Daniel Reichman , Alexander S. Wein

Previously, all known variants of the Quantum Satisfiability (QSAT) problem, i.e. deciding whether a $k$-local ($k$-body) Hamiltonian is frustration-free, could be classified as being either in $\mathsf{P}$; or complete for $\mathsf{NP}$,…

Quantum Physics · Physics 2025-06-10 Ricardo Rivera Cardoso , Alex Meiburg , Daniel Nagaj

What is the minimum amount of information and time needed to solve 2SAT? When the instance is known, it can be solved in polynomial time, but is this also possible without knowing the instance? Bei, Chen and Zhang (STOC '13) considered a…

Computational Complexity · Computer Science 2016-06-14 Itai Arad , Adam Bouland , Daniel Grier , Miklos Santha , Aarthi Sundaram , Shengyu Zhang

Counting ground state degeneracy of a $k$-local Hamiltonian is important in many fields of physics. Its complexity belongs to the problem of sharp bounded-error quantum polynomial time (#BQP) class and few methods are known for its…

Quantum Physics · Physics 2025-10-08 Zhen Guo , Li You

The local Hamiltonian problem consists of estimating the ground-state energy (given by the minimum eigenvalue) of a local quantum Hamiltonian. First, we show the existence of a good product-state approximation for the ground-state energy of…

Quantum Physics · Physics 2016-02-04 Fernando G. S. L. Brandão , Aram W. Harrow

We consider the adiabatic quantum algorithm for systems with "no sign problem", such as the transverse field Ising mode, and analyze the equilibration time for quantum Monte Carlo (QMC) on these systems. We ask: if the spectral gap is only…

Quantum Physics · Physics 2015-10-05 M. B. Hastings , M. H. Freedman

This article shows that PSPACE not equal EXP. A simple but novel proof technique has been used to separate these two classes. Whether an arbitrary Turing machine accepts an input when the running time is limited has been computed in this…

Computational Complexity · Computer Science 2024-03-12 Reiner Czerwinski