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Atomistic simulations are widely used to investigate reactive processes but are often limited by the rare event problem due to kinetic bottlenecks. We recently introduced an enhanced sampling approach based on the committor function,…

Computational Physics · Physics 2026-03-02 Enrico Trizio , Giorgia Rossi , Michele Parrinello

We demonstrate that the Wigner function of a pure quantum state is a wave function in a specially tuned Dirac bra-ket formalism and argue that the Wigner function is in fact a probability amplitude for the quantum particle to be at a…

Quantum Physics · Physics 2013-11-20 Denys I. Bondar , Renan Cabrera , Dmitry V. Zhdanov , Herschel A. Rabitz

Classical molecular dynamics (MD) is a well established and powerful tool in various fields of science, e.g. chemistry, plasma physics, cluster physics and condensed matter physics. Objects of investigation are few-body systems and…

Strongly Correlated Electrons · Physics 2016-02-03 Vladimir Filinov , Michael Bonitz , Alexei Filinov , Volodymyr Golubnychiy

An initial coherent state is propagated exactly by a kicked quantum Hamiltonian and its associated classical stroboscopic map. The classical trajectories within the initial state are regular for low kicking strengths, then bifurcate and…

Chaotic Dynamics · Physics 2019-07-16 Gabriel M. Lando , Alfredo M. Ozorio de Almeida

We introduce a broad class of models called semiparametric spatial point process for making inference between spatial point patterns and spatial covariates. These models feature an intensity function with both parametric and nonparametric…

Methodology · Statistics 2025-09-24 Xindi Lin , Bumjun Park , Christopher Zahasky , Hyunseung Kang

We study conformal quantum mechanics by first considering the perturbative $S$-matrix in various dimensions. The model has two couplings and we study perturbatively the degree of ultraviolet divergences arising in the interplay between the…

Quantum Physics · Physics 2026-04-20 Jacob Hafjall , Thomas A. Ryttov

In this paper, we develop a numerical scheme for the space-time fractional parabolic equation, i.e., an equation involving a fractional time derivative and a fractional spatial operator. Both the initial value problem and the…

Numerical Analysis · Mathematics 2017-08-18 Andrea Bonito , Wenyu Lei , Joseph E. Pasciak

The class of relativistic spin particle models reveals the `quantization' of parameters already at the classical level. The special parameter values emerge if one requires the maximality of classical global continuous symmetries. The same…

High Energy Physics - Theory · Physics 2009-10-31 Mikhail Plyushchay

Linear dynamics restricted to invariant submanifolds generally gives rise to nonlinear dynamics. Submanifolds in the quantum framework may emerge for several reasons: one could be interested in specific properties possessed by a given…

In many physical problems it is not possible to find an exact solution. However, when some parameter in the problem is small, one can obtain an approximate solution by expanding in this parameter. This is the basis of perturbative methods,…

Mathematical Physics · Physics 2007-05-23 Paolo Amore

The goal of this contribution is to introduce the Hamiltonian formalism of theoretical mechanics for analysing motion in generic linear and non-linear dynamical systems, including particle accelerators. This framework allows the derivation…

Accelerator Physics · Physics 2024-02-27 Yannis Papaphilippou

The interconnection between quantum mechanics and probabilistic classical mechanics for a free relativistic particle is derived in terms of Wigner functions (WF) for both Dirac and Klein-Gordon (K-G) equations. Construction of WF is…

High Energy Physics - Theory · Physics 2009-10-31 A. N. Mitra , R. Ramanathan

The parametric ladder climbing (successive Landau-Zener-type transitions) and the quantum saturation of the threshold for the classical parametric autoresonance due to the zero point fluctuations at low temperatures are discussed. The…

Quantum Physics · Physics 2015-06-18 Ido Barth , Lazar Friedland

Applying a Weyl-Stratonovich transform to the evolution equation of the Wigner function in an electromagnetic field yields a multidimensional gauge-invariant equation which is numerically very challenging to solve. In this work, we apply…

Quantum Physics · Physics 2024-03-12 Clemens Etl , Mauro Ballicchia , Mihail Nedjalkov , Josef Weinbub

A continuous sequence of infinitesimal unitary transformations is used to diagonalize the quantum sine-Gordon model for \beta^2\in(2\pi,\infty). This approach can be understood as an extension of perturbative scaling theory since it links…

Statistical Mechanics · Physics 2009-10-31 Stefan Kehrein

The time evolution of the Wigner function for Gaussian states generated by Lindblad quantum dynamics is investigated in the semiclassical limit. A new type of phase-space dynamics is obtained for the centre of a Gaussian Wigner function,…

Quantum Physics · Physics 2019-02-01 E M Graefe , B Longstaff , T Plastow , R Schubert

We present a formalism to compute Lagrangian displacement fields for a wide range of cosmologies in the context of perturbation theory up to third order. We emphasize the case of theories with scale dependent gravitational strengths, such…

Cosmology and Nongalactic Astrophysics · Physics 2018-01-16 Alejandro Aviles , Jorge L. Cervantes-Cota

The Yang-Mills gradient flow for QCD-like theories is generalized by including a fermionic matter term in the gauge field flow equation. We combine this with two different flow equations for the fermionic degrees of freedom. The solutions…

High Energy Physics - Theory · Physics 2021-02-24 Marco Boers

We develop a modified semi-classical approach to the approximate solution of Schrodinger's equation for certain nonlinear quantum oscillations problems. At lowest order, the Hamilton-Jacobi equation of the conventional semi-classical…

Mathematical Physics · Physics 2015-06-03 Vincent Moncrief , Antonella Marini , Rachel Maitra

In this paper, we develop a nonparametric system identification method for the nonlinear gradient-flow dynamics. In these systems, the vector field is the gradient field of a potential energy function. This fundamental fact about the…

Optimization and Control · Mathematics 2020-03-30 Mohammad Khosravi , Roy S. Smith