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Related papers: Hardness of approximation for quantum problems

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This article surveys quantum computational complexity, with a focus on three fundamental notions: polynomial-time quantum computations, the efficient verification of quantum proofs, and quantum interactive proof systems. Properties of…

Quantum Physics · Physics 2008-04-23 John Watrous

Practical challenges in simulating quantum systems on classical computers have been widely recognized in the quantum physics and quantum chemistry communities over the past century. Although many approximation methods have been introduced,…

We construct explicit easily implementable polynomial approximations of sufficiently high accuracy for locally constant functions on the union of disjoint segments. This problem has important applications in several areas of numerical…

Functional Analysis · Mathematics 2023-11-29 Yuri Malykhin , Konstantin Ryutin

In this paper, we propose two new methods for solving Set Constraint Problems, as well as a potential polynomial solution for NP-Complete problems using quantum computation. While current methods of solving Set Constraint Problems focus on…

Logic in Computer Science · Computer Science 2025-04-29 Neema Rustin Badihian

In a recent preprint by Deutsch et al. [1995] the authors suggest the possibility of polynomial approximability of arbitrary unitary operations on $n$ qubits by 2-qubit unitary operations. We address that comment by proving strong lower…

Quantum Physics · Physics 2008-02-03 E. Knill

A critical milestone on the path to useful quantum computers is quantum supremacy - a demonstration of a quantum computation that is prohibitively hard for classical computers. A leading near-term candidate, put forth by the Google/UCSB…

Quantum Physics · Physics 2020-11-13 Adam Bouland , Bill Fefferman , Chinmay Nirkhe , Umesh Vazirani

We develop a theory of the algorithmic information in bits contained in an individual pure quantum state. This extends classical Kolmogorov complexity to the quantum domain retaining classical descriptions. Quantum Kolmogorov complexity…

Quantum Physics · Physics 2016-11-17 Paul M. B. Vitanyi

The computational complexity of simulating the dynamics of physical quantum systems is a central question at the interface of quantum physics and computer science. In this work, we address this question for the simulation of exponentially…

Quantum Physics · Physics 2026-04-15 Lilith Zschetzsche , Refik Mansuroglu , Norbert Schuch

Query complexity is a model of computation in which we have to compute a function $f(x_1, \ldots, x_N)$ of variables $x_i$ which can be accessed via queries. The complexity of an algorithm is measured by the number of queries that it makes.…

Quantum Physics · Physics 2017-12-19 Andris Ambainis

Density modelling is the task of learning an unknown probability density function from samples, and is one of the central problems of unsupervised machine learning. In this work, we show that there exists a density modelling problem for…

Quantum Physics · Physics 2023-04-17 Niklas Pirnay , Ryan Sweke , Jens Eisert , Jean-Pierre Seifert

We consider a version of the nearest-codeword problem on finite fields $\mathbb{F}_q$ using the Manhattan distance, an analog of the Hamming metric for non-binary alphabets. Similarly to other lattice related problems, this problem is…

Quantum Physics · Physics 2023-09-13 Lior Eldar

A test on the numerical accuracy of the semiclassical approximation as a function of the principal quantum number has been performed for the Pullen--Edmonds model, a two--dimensional, non--integrable, scaling invariant perturbation of the…

High Energy Physics - Theory · Physics 2009-09-25 S. Graffi , V. R. Manfredi , L. Salasnich

The classical PCP theorem is arguably the most important achievement of classical complexity theory in the past quarter century. In recent years, researchers in quantum computational complexity have tried to identify approaches and develop…

Quantum Physics · Physics 2013-10-01 Dorit Aharonov , Itai Arad , Thomas Vidick

A basic problem of approximation theory, the approximation of functions from the Sobolev space W_p^r([0,1]^d) in the norm of L_q([0,1]^d), is considered from the point of view of quantum computation. We determine the quantum query…

Quantum Physics · Physics 2007-05-23 Stefan Heinrich

As we begin to reach the limits of classical computing, quantum computing has emerged as a technology that has captured the imagination of the scientific world. While for many years, the ability to execute quantum algorithms was only a…

Quantum Physics · Physics 2020-11-12 Bela Bauer , Sergey Bravyi , Mario Motta , Garnet Kin-Lic Chan

Quantum computing involving physical systems with continuous degrees of freedom, such as the quantum states of light, has recently attracted significant interest. However, a well-defined quantum complexity theory for these bosonic…

Quantum Physics · Physics 2026-05-20 Ulysse Chabaud , Michael Joseph , Saeed Mehraban , Arsalan Motamedi

We give a general method for proving quantum lower bounds for problems with small range. Namely, we show that, for any symmetric problem defined on functions $f:\{1, ..., N\}\to\{1, ..., M\}$, its polynomial degree is the same for all…

Quantum Physics · Physics 2008-05-12 Andris Ambainis

After nearly two decades of research, the question of a quantum PCP theorem for quantum Constraint Satisfaction Problems (CSPs) remains wide open. As a result, proving QMA-hardness of approximation for ground state energy estimation has…

Quantum Physics · Physics 2024-11-08 Sevag Gharibian , Carsten Hecht

The calculation of ground-state energies of physical systems can be formalised as the k-local Hamiltonian problem, which is the natural quantum analogue of classical constraint satisfaction problems. One way of making the problem more…

Quantum Physics · Physics 2016-03-29 Toby Cubitt , Ashley Montanaro

Quantum deformations of sets of points of the real and the complexified projective line are constructed. These deformations depend on the deformation parameter q and certain further parameters \lambda_{ij}. The deformations for which the…

Quantum Algebra · Mathematics 2009-11-11 Frank Leitenberger