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This work discusses the finite element discretization of an optimal control problem for the linear wave equation with time-dependent controls of bounded variation. The main focus lies on the convergence analysis of the discretization…

Optimization and Control · Mathematics 2019-07-26 Sebastian Engel , Philip Trautmann , Boris Vexler

Quantum machine learning for classical data is currently perceived to have a scalability problem due to (i) a bottleneck at the point of loading data into quantum states, (ii) the lack of clarity around good optimization strategies, and…

Quantum Physics · Physics 2025-01-09 Sonika Johri

We reconsider the geometrically nonlinear Cosserat model for a uniformly convex elastic energy and write the equilibrium problem as a minimization problem. Applying the direct methods of the calculus of variations we show the existence of…

Analysis of PDEs · Mathematics 2014-12-16 Patrizio Neff , Mircea Bîrsan , Frank Osterbrink

Obtaining guarantees on the convergence of the minimizers of empirical risks to the ones of the true risk is a fundamental matter in statistical learning. Instead of deriving guarantees on the usual estimation error, the goal of this paper…

Statistics Theory · Mathematics 2024-09-12 Paul Escande

Standard variational methods tend to obtain upper bounds on the ground state energy of quantum many-body systems. Here we study a complementary method that determines lower bounds on the ground state energy in a systematic fashion, scales…

Quantum Physics · Physics 2015-05-28 Tillmann Baumgratz , Martin B. Plenio

We study minimizers of non-autonomous energies with minimal growth and coercivity assumptions on the energy. We show that the minimizer is nevertheless the solution of the relevant Euler--Lagrange equation or inequality. The main tool is an…

Analysis of PDEs · Mathematics 2025-04-04 Petteri Harjulehto , Peter Hästö , Andrea Torricelli

The macroscopic hydrodynamic equations are derived for many-body systems in the local-equilibrium approach, using the Schr\"odinger picture of quantum mechanics. In this approach, statistical operators are defined in terms of microscopic…

Statistical Mechanics · Physics 2023-01-18 Joël Mabillard , Pierre Gaspard

A conjecture on the origin of elementary particle masses is discussed, based on the micro-universe and quantum state reduction concepts. The reduction of the quantum state of a real particle is understood to take place objectively; in every…

General Physics · Physics 2009-05-26 L. Chiatti

This article addresses a number of issues associated with the problem of calculating contributions from the electromagnetic quantum induced energy and stress in a stationary material with an inhomogeneous polarizability. After briefly…

Quantum Physics · Physics 2018-10-01 S. Goto , R. W. Tucker , T. J. Walton

We consider a constrained minimal energy problem with an external field over noncompact classes of infinite dimensional vector measures on a locally compact space. The components are positive measures (charges) that are constrained from…

Classical Analysis and ODEs · Mathematics 2010-10-12 Natalia Zorii

We define a deformed kinetic energy operator for a discrete position space with a finite number of points. The structure may be either periodic or nonperiodic with well-defined end points. It is shown that for the nonperiodic case the…

Quantum Physics · Physics 2016-06-21 Metin Arik , Medine Ildes

A reinforcement algorithm solves a classical optimization problem by introducing a feedback to the system which slowly changes the energy landscape and converges the algorithm to an optimal solution in the configuration space. Here, we use…

Disordered Systems and Neural Networks · Physics 2017-11-08 A. Ramezanpour

Although quantum computing hardware has evolved significantly in recent years, spurred by increasing industrial and government interest, the size limitation of current generation quantum computers remains an obstacle when applying these…

Quantum Physics · Physics 2020-01-20 Gideon Bass , Max Henderson , Joshua Heath , Joseph Dulny

We investigate the equilibration of a small isolated quantum system by means of its matrix of asymptotic transition probabilities in a preferential basis. The trace of this matrix is shown to measure the degree of equilibration of the…

Statistical Mechanics · Physics 2016-02-04 J. M. Luck

The regularized vacuum energy (or energy density) of a quantum field subjected to static external conditions is shown to satisfy a certain partial differential equation with respect to two variables, the mass and the "time" (ultraviolet…

Mathematical Physics · Physics 2009-11-11 S. A. Fulling

A fundamental problem in quantum physics is to establish whether a multiparticle quantum state can be uniquely determined from its local marginals. In theory, this problem has been addressed in the exact case where the marginals are…

Quantum Physics · Physics 2026-04-08 Wenjun Yu , Fei Shi , Giulio Chiribella , Qi Zhao

This paper is concerned with the rigorous analysis of a recently proposed model of Zheng et. al. for describing nematic liquid crystals within the dense regime, with the orientation distribution function as the variable. A key feature of…

Analysis of PDEs · Mathematics 2017-03-01 Jamie M. Taylor

We consider the problem of solving a distributed optimization problem using a distributed computing platform, where the communication in the network is limited: each node can only communicate with its neighbours and the channel has a…

Systems and Control · Computer Science 2015-04-10 Ye Pu , Melanie N. Zeilinger , Colin N. Jones

Quantum mechanics does not provide any ready recipe for defining energy density in space, since the energy and coordinate do not commute. To find a well-motivated energy density, we start from a possibly fundamental, relativistic…

Quantum Physics · Physics 2024-01-17 V. Stepanyan , A. E. Allahverdyan

The effective classical/quantum dynamics of a particle constrained on a closed line embedded in a higher dimensional configuration space is analyzed. By considering explicit examples it is shown how different reduction mechanisms produce…

High Energy Physics - Theory · Physics 2007-05-23 P. Maraner