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We investigate the quantum algorithms for dynamic programming by Ambainis et al. (SODA'19). While giving provable complexity speedups and applicable to a variety of NP-hard problems, these algorithms have a notable drawback: they require a…

Quantum Physics · Physics 2026-04-03 Susanna Caroppo , Jevgēnijs Vihrovs , Dārta Zajakina , Aleksejs Zajakins

We analyze the Schr\"odingerization method for quantum simulation of a general class of non-unitary dynamics with inhomogeneous source terms. The Schr\"odingerization technique, introduced in [31], transforms any linear ordinary and partial…

Numerical Analysis · Mathematics 2025-04-15 Shi Jin , Nana Liu , Chuwen Ma

Quantum dynamics, typically expressed in the form of a time-dependent Schr\"odinger equation with a Hermitian Hamiltonian, is a natural application for quantum computing. However, when simulating quantum dynamics that involves the emission…

Quantum Physics · Physics 2023-04-04 Shi Jin , Nana Liu , Xiantao Li , Yue Yu

The main aim of this note is to show that the formalism of multi-time equations in quantum mechanics meant to represent a manifestly Lorentz-invariant theory suffers from at least three imperfections: (1) It does not cover those physical…

Quantum Physics · Physics 2014-03-04 Ali Sanayei

The traditional approach to accelerator optics, based mainly on classical mechanics, is working excellently from the practical point of view. However, from the point of view of curiosity, as well as with a view to explore quantitatively the…

Accelerator Physics · Physics 2007-05-23 R. Jagannathan

In this paper, a second order finite difference scheme is investigated for time-dependent one-side space fractional diffusion equations with variable coefficients. The existing schemes for the equation with variable coefficients have…

Numerical Analysis · Mathematics 2019-02-25 Xue-lei Lin , Pin Lyu , Michael K. Ng , Hai-Wei Sun , Seakweng Vong

We propose a way to accelerate adiabatic dynamics of wave functions in quantum mechanics to obtain a final adiabatic state except for the spatially uniform phase in any desired short time. We develop the previous theory of fast-forward…

Mesoscale and Nanoscale Physics · Physics 2015-05-14 Shumpei Masuda , Katsuhiro Nakamura

The design of quantum control methods has been shown to greatly improve the performance of many evolving quantum technologies. To this end, the usage of adiabatic dynamics to drive quantum systems is seriously limited by the action of…

Quantum Physics · Physics 2020-02-12 Bertúlio de Lima Bernardo

By parametrizing the action integral for the standard Schrodinger equation we present a derivation of the recently proposed method for quantizing a parametrized theory. The reformulation suggests a natural extension from conventional to…

General Relativity and Quantum Cosmology · Physics 2009-11-10 Charles H-T Wang , Smaragda Kessari , Edward R Irvine

Covariant phase space quantization attempts to quantize the full space of classical solutions, leading to a quantum theory in which the usual time coordinate is missing. In this paper we explore how the time evolution of the quantum states…

General Relativity and Quantum Cosmology · Physics 2022-12-15 Weixuan Hu

In it's usual presentation, classical mechanics appears to give time a very special role. But it is well known that mechanics can be formulated so as to treat the time variable on the same footing as the other variables in the extended…

General Relativity and Quantum Cosmology · Physics 2016-08-31 Michael Reisenberger , Carlo Rovelli

One of the greatest scientific achievements of physics in the 20th century is the discovery of quantum mechanics. The Schrodinger equation is the most fundamental equation in quantum mechanics describing the time-based evolution of the…

Optimization and Control · Mathematics 2009-02-11 Xiaofei Huang

We give a partial review of what is known so far on stability of periodically driven quantum systems versus regularity of the bounded driven force. In particular we emphasize the fact that unbounded degeneracies of the unperturbed…

Mathematical Physics · Physics 2007-05-23 P. Duclos , O. Lev , P. Stovicek , M. Vittot

The long-standing problem of time in canonical quantum gravity is the source of several conceptual and technical issues. Here, recent mathematical results are used to provide a consistent algebraic formulation of dynamical symplectic…

General Relativity and Quantum Cosmology · Physics 2023-01-04 Martin Bojowald , Artur Tsobanjan

Adiabatic processes are important for studying the dynamics of a time-dependent system. Conventionally, the adiabatic processes can only be achieved by varying the system slowly. We speed up both classical and quantum adiabatic processes by…

Quantum Physics · Physics 2013-05-21 Jia-wen Deng , Qing-hai Wang , Jiangbin Gong

The Schrodinger equation, Klein-Gordon equation (KGE), and Dirac equation are believed to be the fundamental equations of quantum mechanics. Schrodinger's equation has a defect in that there are no negative kinetic energy (NKE) solutions.…

General Physics · Physics 2022-05-09 Huai-Yu Wang

Quantum simulation is known to be capable of simulating certain dynamical systems in continuous time -- Schrodinger's equations being the most direct and well-known -- more efficiently than classical simulation. Any linear dynamical system…

Quantum Physics · Physics 2025-04-22 Shi Jin , Nana Liu

In this article we investigate and solve exactly the modified Dirac oscillator in curved spacetime with spin and pseudospin symmetries through an algebraic approach. By focusing on the radial part of this problem, we use the Schr\"odinger…

We propose a Fourier pseudo-spectral scheme for the space-fractional nonlinear Schr\"odinger equation. The proposed scheme has the following features: it is linearly implicit, it preserves two invariants of the equation, its unique…

Numerical Analysis · Mathematics 2019-09-04 Yuto Miyatake , Tai Nakagawa , Tomohiro Sogabe , Shao-Liang Zhang

Quantum counterparts of Schrodinger's classical bridge problem have been around for the better part of half a century. During that time, several quantum approaches to this multifaceted classical problem have been introduced. In the present…

Quantum Physics · Physics 2025-03-11 Olga Movilla Miangolarra , Ralph Sabbagh , Tryphon T. Georgiou