English
Related papers

Related papers: Euclidean Quantum Mechanics and Universal Nonlinea…

200 papers

The Feynman path integral plays a crucial role in quantum mechanics, offering significant insights into the interaction between classical action and propagators, and linking quantum electrodynamics (QED) with Feynman diagrams. However, the…

General Physics · Physics 2026-05-19 W. Wen

This paper presents a systematic review of recent advances in nonlinear filtering algorithms, structured into three principal categories: Kalman-type methods, Monte Carlo methods, and the Yau-Yau algorithm. For each category, we provide a…

Optimization and Control · Mathematics 2026-02-11 Chang Qin , Yikun Li , Ru Qian , Jiayi Kang , Yao Mao

The path integral approach to the quantization of one degree-of-freedom Newtonian particles is considered within the discrete time-slicing approach, as in Feynman's original development. In the time-slicing approximation the quantum…

Exactly Solvable and Integrable Systems · Physics 2009-11-11 Chris M. Field , Frank W. Nijhoff

Quantum measurement problem is still unconsensus since it has existed many years and inspired a large of literature in physics and philosophy. We show it can be subsumed into the quantum theory if we extend the Feynman path integral by…

Quantum Physics · Physics 2012-03-12 Wei Wen

We review a possible framework for (non)linear quantum theories, into which linear quantum mechanics fits as well, and discuss the notion of ``equivalence'' in this setting. Finally, we draw the attention to persisting severe problems of…

Quantum Physics · Physics 2007-05-23 Peter Nattermann

We derive the form of the Belavkin-Kushner-Stratonovich equation describing the filtering of a continuous observed quantum system via non-demolition measurements when the statistics of the input field used for the indirect measurement are…

Mathematical Physics · Physics 2013-03-06 John Gough , Claus Kostler

We study quantum mechanical tunneling using complex solutions of the classical field equations. Simple visualization techniques allow us to unify and generalize previous treatments, and straightforwardly show the connection to the standard…

High Energy Physics - Theory · Physics 2016-09-21 Sebastian F. Bramberger , George Lavrelashvili , Jean-Luc Lehners

Quantum mechanical systems exhibit an inherently probabilistic nature upon measurement. Using a quantum noise model to describe the stochastic evolution of the open quantum system and working in parallel with classical indeterministic…

Quantum Physics · Physics 2007-05-23 S. C. Edwards , V. P. Belavkin

A numerical scheme for approximating the nonlinear filtering density is introduced and its convergence rate is established, theoretically under a parabolic H\"{o}rmander condition, and empirically in numerical examples. In a prediction…

Numerical Analysis · Mathematics 2026-04-21 Kasper Bågmark , Adam Andersson , Stig Larsson , Filip Rydin

The Feynman path integral approach to quantum mechanics is examined in the case where the configuration space is curved. It is shown how the ambiguity that is present in the choice of path integral measure may be resolved if, in addition to…

High Energy Physics - Theory · Physics 2007-05-23 David J. Toms

In this paper we consider the continuous--time nonlinear filtering problem, which has an infinite--dimensional solution in general, as proved by Chaleyat--Maurel and Michel. There are few examples of nonlinear systems for which the optimal…

Probability · Mathematics 2009-01-15 Damiano Brigo

A new Langevin equation with a field-dependent kernel is proposed to deal with bottomless systems within the framework of the stochastic quantization of Parisi and Wu. The corresponding Fokker-Planck equation is shown to be a diffusion-type…

High Energy Physics - Theory · Physics 2009-10-22 Hiromichi Nakazato

We show the linking-type result which allows us to study strongly indefinite problems with sign-changing nonlinearities. We apply the abstract theory to the singular Schr\"{o}dinger equation $$ -\Delta u + V(x)u + \frac{a}{r^2} u = f(u) -…

Analysis of PDEs · Mathematics 2023-02-28 Federico Bernini , Bartosz Bieganowski

Quantum mechanical systems exhibit an inherently probabilistic nature upon measurement which excludes in principle the singular direct observability continual case. Quantum theory of time continuous measurements and quantum prediction…

Mathematical Physics · Physics 2007-05-23 V. P. Belavkin

Discretizations of the Feynman-Kac path integral representation of the quantum mechanical density matrix are investigated. Each infinite-dimensional path integral is approximated by a Riemann integral over a finite-dimensional function…

Statistical Mechanics · Physics 2007-05-23 Stephen D. Bond , Brian B. Laird , Benedict J. Leimkuhler

Quantum mechanics in its presently known formulation requires an external classical time for its description. A classical spacetime manifold and a classical spacetime metric are produced by classical matter fields. In the absence of such…

General Relativity and Quantum Cosmology · Physics 2008-11-26 T. P. Singh

If quantum states exhibit small nonlinearities during time evolution, then quantum computers can be used to solve NP-complete problems in polynomial time. We provide algorithms that solve NP-complete and #P oracle problems by exploiting…

Quantum Physics · Physics 2009-10-31 Daniel S. Abrams , Seth Lloyd

Feynman path integrals are now a standard tool in quantum physics and their use in differential geometry leads to new mathematical insights. A logical treatment of quantum phenomena seems to require a sustained mathematical analysis of path…

Mathematical Physics · Physics 2022-04-18 B. R. F. Jefferies

We discuss the approach to equilibrium of systems governed by the Fokker-Planck equation. In particular, we focus on problems involving barrier penetration and the associated Kramers' time. We also describe the connection between stochastic…

Statistical Mechanics · Physics 2007-05-23 Himadri S. Samanta , J. K. Bhattacharjee

All measurable predictions of classical mechanics can be reproduced from a quantum-like interpretation of a nonlinear Schrodinger equation. The key observation leading to classical physics is the fact that a wave function that satisfies a…

Quantum Physics · Physics 2014-11-18 H. Nikolic