English
Related papers

Related papers: Lower bounds to variational problems with guarante…

200 papers

We provide rigorous theoretical bounds for Anderson acceleration (AA) that allow for approximate calculations when applied to solve linear problems. We show that, when the approximate calculations satisfy the provided error bounds, the…

Numerical Analysis · Mathematics 2024-04-30 Massimiliano Lupo Pasini , M. Paul Laiu

The Fermi-Hubbard model is of fundamental importance in condensed-matter physics, yet is extremely challenging to solve numerically. Finding the ground state of the Hubbard model using variational methods has been predicted to be one of the…

Quantum Physics · Physics 2021-01-04 Chris Cade , Lana Mineh , Ashley Montanaro , Stasja Stanisic

This survey on stationary and evolutionary problems with gradient constraints is based on developments of monotonicity and compactness methods applied to large classes of scalar and vectorial solutions to variational and quasi-variational…

Analysis of PDEs · Mathematics 2018-09-07 José Francisco Rodrigues , Lisa Santos

We introduce a new type of boundary conditions, {\it smooth boundary conditions}, for numerical studies of quantum lattice systems. In a number of circumstances, these boundary conditions have substantially smaller finite-size effects than…

Condensed Matter · Physics 2009-10-22 M. Vekic , S. R. White

Simulating the Hubbard model is of great interest to a wide range of applications within condensed matter physics, however its solution on classical computers remains challenging in dimensions larger than one. The relative simplicity of…

Quantum Physics · Physics 2025-05-21 Antonios M. Alvertis , Abid Khan , Thomas Iadecola , Peter P. Orth , Norm Tubman

Variational methods are employed in situations where exact Bayesian inference becomes intractable due to the difficulty in performing certain integrals. Typically, variational methods postulate a tractable posterior and formulate a lower…

Machine Learning · Statistics 2019-06-12 Nikolaos Gianniotis , Christoph Schnörr , Christian Molkenthin , Sanjay Singh Bora

Advantages of using a low-energy effective theory to study bound state properties are briefly discussed, and a nonperturbative implementation of such an effective theory is described within the context of nonrelativistic quantum mechanics.…

High Energy Physics - Phenomenology · Physics 2009-10-31 Richard Hill

We present numerical solutions to the extended Doering-Constantin variational principle for upper bounds on the energy dissipation rate in turbulent plane Couette flow. Using the compound matrix technique in order to reformulate this…

Soft Condensed Matter · Physics 2009-10-31 Rolf Nicodemus , Siegfried Grossmann , Martin Holthaus

We study random Hamiltonians on finite-size cubes and waveguide segments of increasing diameter. The number of random parameters determining the operator is proportional to the volume of the cube. In the asymptotic regime where the cube…

Analysis of PDEs · Mathematics 2016-01-15 Denis Borisov , Anastasia Golovina , Ivan Veselic

It is known that the variational methods are the most powerful tool for studying the Coulomb three-body bound state problem. However, they often suffer from loss of stability when the number of basis functions increases. This problem can be…

Atomic Physics · Physics 2016-09-08 V. I. Korobov

We define a numerical scheme that allows to approximate a given Hamiltonian by an effective one, by requiring several constraints determined by exact properties of generic ''short range'' Hamiltonians. In this way the standard lattice fixed…

Strongly Correlated Electrons · Physics 2009-11-10 Sandro Sorella , Seiji Yunoki

In this paper, we present a method to solve the quantum marginal problem for symmetric $d$-level systems. The method is built upon an efficient semi-definite program that determines the compatibility conditions of an $m$-body reduced…

Quantum Physics · Physics 2021-05-26 Albert Aloy , Matteo Fadel , Jordi Tura

The paper presents a variational quantum algorithm to solve initial-boundary value problems described by second-order partial differential equations. The approach uses hybrid classical/quantum hardware that is well suited for quantum…

Variational inference has become one of the most widely used methods in latent variable modeling. In its basic form, variational inference employs a fully factorized variational distribution and minimizes its KL divergence to the posterior.…

Machine Learning · Statistics 2020-01-29 Robert Bamler , Cheng Zhang , Manfred Opper , Stephan Mandt

We show how to optimally reduce the local Hilbert basis of lattice quantum many-body (QMB) Hamiltonians. The basis truncation exploits the most relevant eigenvalues of the estimated single-site reduced density matrix (RDM). It is accurate…

Strongly Correlated Electrons · Physics 2025-09-23 Peter Majcen , Giovanni Cataldi , Pietro Silvi , Simone Montangero

We propose a qubit efficient scheme to study ground state properties of quantum many-body systems on near-term noisy intermediate scale quantum computers. One can obtain a tensor network representation of the ground state using a number of…

Quantum Physics · Physics 2019-10-02 Jin-Guo Liu , Yi-Hong Zhang , Yuan Wan , Lei Wang

The ground state properties of quantum many-body systems are a subject of interest across chemistry, materials science, and physics. Thus, algorithms for finding ground states can have broad impacts. Variational quantum algorithms are one…

Quantum Physics · Physics 2023-09-28 James B. Larsen , Matthew D. Grace , Andrew D. Baczewski , Alicia B. Magann

We present a relaxation-based method to bound expectation values on the steady state of dissipative many-body quantum systems described by master equations of the Lindblad form. Instead of targeting to represent the entire state, we promote…

Quantum Physics · Physics 2026-02-09 Miguel Frías Pérez , Antonio Acín

We present a novel generic framework to approximate the non-equilibrium steady states of dissipative quantum many-body systems. It is based on the variational minimization of a suitable norm of the quantum master equation describing the…

Quantum Physics · Physics 2015-02-20 Hendrik Weimer

Recent technological developments have focused the interest of the quantum computing community on investigating how near-term devices could outperform classical computers for practical applications. A central question that remains open is…

Quantum Physics · Physics 2021-11-24 Daniel Stilck Franca , Raul Garcia-Patron