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We provide a numerically robust and fast method capable of exploiting the local geometry when solving large-scale stochastic optimisation problems. Our key innovation is an auxiliary variable construction coupled with an inverse Hessian…

Machine Learning · Statistics 2018-02-14 Adrian Wills , Thomas Schön

We present an algorithm for the simulation of the exact real-time dynamics of classical many-body systems with discrete energy levels. In the same spirit of kinetic Monte Carlo methods, a stochastic solution of the master equation is found,…

Statistical Mechanics · Physics 2016-07-20 Alejandro Mendoza-Coto , Rogelio Díaz-Méndez , Guido Pupillo

In this paper, we extend the adaptive partition-based approach for solving two-stage stochastic programs with fixed recourse to the multistage stochastic programming setting. The proposed algorithms integrate the adaptive partition-based…

Optimization and Control · Mathematics 2019-08-30 Murwan Siddig , Yongjia Song

The quantum-classical Liouville equation offers a rigorous approach to nonadiabatic quantum dynamics based on surface hopping type trajectories. However, in practice the applicability of this approach has been limited to short times owing…

Chemical Physics · Physics 2015-06-16 Aaron Kelly , Thomas E. Markland

The theoretical investigation of non-adiabatic processes is hampered by the complexity of the coupled electron-nuclear dynamics beyond the Born-Oppenheimer approximation. Classically, the simulation of such reactions is limited by the…

Quantum Physics · Physics 2021-01-06 Pauline J. Ollitrault , Guglielmo Mazzola , Ivano Tavernelli

We are interested in high-order linear multistep schemes for time discretization of adjoint equations arising within optimal control problems. First we consider optimal control problems for ordinary differential equations and show loss of…

Numerical Analysis · Mathematics 2018-07-24 Giacomo Albi , Michael Herty , Lorenzo Pareschi

In this paper we consider the inverse problem of identifying the initial data in a fractionally damped wave equation from time trace measurements on a surface, as relevant in photoacoustic or thermoacoustic tomography. We derive and analyze…

Numerical Analysis · Mathematics 2021-11-24 Barbara Kaltenbacher , Anna Schlintl

Decentralized learning recently has received increasing attention in machine learning due to its advantages in implementation simplicity and system robustness, data privacy. Meanwhile, the adaptive gradient methods show superior…

Machine Learning · Computer Science 2024-08-20 Feihu Huang , Jianyu Zhao

Quantum-phase-estimation algorithms are critical subroutines in many applications for quantum computers and in quantum-metrology protocols. These algorithms estimate the unknown strength of a unitary evolution. By using coherence or…

Quantum Physics · Physics 2023-03-06 Joseph G. Smith , Crispin H. W. Barnes , David R. M. Arvidsson-Shukur

We present a numerical scheme for approximating the incompressible Navier-Stokes equations based on an auxiliary variable associated with the total system energy. By introducing a dynamic equation for the auxiliary variable and…

Fluid Dynamics · Physics 2019-05-01 Lianlei Lin , Suchuan Dong

Difference schemes are considered for dynamical systems $ \dot x = f (x) $ with a quadratic right-hand side, which have $t$-symmetry and are reversible. Reversibility is interpreted in the sense that the Cremona transformation is performed…

Classical Analysis and ODEs · Mathematics 2024-12-03 Mikhail Malykh , Leonid Sevastianov

A scheme for stabilizing stochastic approximation iterates by adaptively scaling the step sizes is proposed and analyzed. This scheme leads to the same limiting differential equation as the original scheme and therefore has the same…

Probability · Mathematics 2010-07-28 Sameer Kamal

The development of finite/fixed-time stable optimization algorithms typically involves study of specific problem instances. The lack of a unified framework hinders understanding of more sophisticated algorithms, e.g., primal-dual gradient…

Optimization and Control · Mathematics 2024-09-19 Ibrahim K. Ozaslan , Mihailo R. Jovanović

Many recently introduced enhanced sampling techniques are based on biasing coarse descriptors (collective variables) of a molecular system on the fly. Sometimes the calculation of such collective variables is expensive and becomes a…

Computational Physics · Physics 2015-09-01 Marco Jacopo Ferrarotti , Sandro Bottaro , Andrea Pérez-Villa , Giovanni Bussi

The effective approach to quantum dynamics allows a reformulation of the Dirac quantization procedure for constrained systems in terms of an infinite-dimensional constrained system of classical type. For semiclassical approximations, the…

General Relativity and Quantum Cosmology · Physics 2011-07-20 Martin Bojowald , Philipp A Hoehn , Artur Tsobanjan

We present an explicit multiscale algorithm for solving differential equations for problems with high-frequency modes that can be averaged over by separating and scaling the fast and slow dynamics within a single equation. We introduce a…

Plasma Physics · Physics 2026-05-29 Maxwell H. Rosen , Manaure Francisquez , Gregory W. Hammett

Two specialized algorithms for the numerical integration of the equations of motion of a Brownian walker obeying detailed balance are introduced. The algorithms become symplectic in the appropriate limits, and reproduce the equilibrium…

Statistical Mechanics · Physics 2009-11-10 R Mannella

We present a general numerical scheme for the practical implementation of statistical moment closures suitable for modeling complex, large-scale, nonlinear systems. Building on recently developed equation-free methods, this approach…

Statistical Mechanics · Physics 2009-11-13 Francis J. Alexander , Gregory Johnson , Gregory L. Eyink , Ioannis G. Kevrekidis

Multiple time-scale algorithms exploit the natural separation of time-scales in chemical systems to greatly accelerate the efficiency of molecular dynamics simulations. Although the utility of these methods in systems where the interactions…

Computational Physics · Physics 2015-06-18 Nathan Luehr , Thomas E. Markland , Todd J. Martinez

Quantum phase estimation is one of the most important tools in quantum algorithms. It can be made non-adaptive (meaning all applications of the unitary $U_\phi$ happen simultaneously) without using more applications of $U_\phi$, albeit at…

Quantum Physics · Physics 2025-11-10 Noah Linden , Ronald de Wolf