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The objective of this paper is to investigate a new numerical method for the approximation of the self-diffusion matrix of a tagged particle process defined on a grid. While standard numerical methods make use of long-time averages of…

Numerical Analysis · Mathematics 2023-02-27 Jad Dabaghi , Virginie Ehrlacher , Christoph Strössner

Metallic nano-structures characterised by multiple geometric length scales support low-frequency surface-plasmon modes, which enable strong light localization and field enhancement. We suggest studying such configurations using singular…

Mesoscale and Nanoscale Physics · Physics 2015-12-23 Ory Schnitzer

Time harmonic inverse scattering using accurate forward models is often computationally expensive. On the other hand, the use of computationally efficient solvers, such as the Born approximation, may fail if the targets do not satisfy the…

Computational Physics · Physics 2019-07-05 Jari P. Kaipio , Tomi Huttunen , Teemu Luostari , Timo Lähivaara , Peter B. Monk

We are interested in numerically solving a transitional model derived from the Bloch model. The Bloch equation describes the time evolution of the density matrix of a quantum system forced by an electromagnetic wave. In a high frequency and…

Analysis of PDEs · Mathematics 2023-08-02 Brigitte Bidégaray-Fesquet , Clément Jourdana , Léopold Trémant

This paper presents an overview of the Fokker-Planck formalism for non-biological magnetic resonance simulations, describes its existing applications and proposes some novel ones. The most attractive feature of Fokker-Planck theory compared…

Quantum Physics · Physics 2016-07-27 Ilya Kuprov

This paper extends the Method of Particular Solutions (MPS) to the computation of eigenfrequencies and eigenmodes of plates. Specific approximation schemes are developed, with plane waves (MPS-PW) or Fourier-Bessel functions (MPS-FB). This…

Numerical Analysis · Mathematics 2013-04-09 Gilles Chardon , Laurent Daudet

We show that the pressure associated with a distributional solution of the Navier-Stokes equations on the whole space satisfies a local expansion defined as a distribution if and only if the solution is mild. This gives a new perspective on…

Analysis of PDEs · Mathematics 2020-02-03 Zachary Bradshaw , Tai-Peng Tsai

Partial differential equations are frequently solved using a global basis, such as the Fourier series, due to excellent convergence. However, convergence becomes impaired when discontinuities are present due to the Gibbs phenomenon,…

Computational Physics · Physics 2021-03-17 Parry Y Chen , Yonatan Sivan

We study the canonical problem of wave scattering by periodic arrays, either of infinite or finite extent, of Neumann scatterers in the plane; the characteristic lengthscale of the scatterers is considered small relative to the lattice…

Computational Physics · Physics 2020-09-28 Richard Wiltshaw , Richard V. Craster , Mehul P. Makwana

The global-in-time existence and uniqueness of bounded weak solutions to a spinorial matrix drift-diffusion model for semiconductors is proved. Developing the electron density matrix in the Pauli basis, the coefficients (charge density and…

Analysis of PDEs · Mathematics 2013-12-10 Ansgar Jüngel , Claudia Negulescu , Polina Shpartko

In order to reduce the computational cost of the simulation of electromagnetic responses in geophysical settings that involve highly heterogeneous media, we develop a multiscale finite volume method with oversampling for the quasi-static…

Computational Physics · Physics 2016-10-10 Luz Angelica Caudillo Mata , Eldad Haber , Christoph Schwarzbach

The approximation of probability measures on compact metric spaces and in particular on Riemannian manifoldsby atomic or empirical ones is a classical task in approximation and complexity theory with a wide range of applications. Instead of…

Optimization and Control · Mathematics 2021-01-12 Martin Ehler , Manuel Gräf , Sebastian Neumayer , Gabriele Steidl

The perturbation of a magnetostatic field by a toroid made of a homogeneous anisotropic magnetic material was formulated using the solutions of the Laplace equation in the toroidal coordinate system. That was straightforward in the region…

Classical Physics · Physics 2025-04-11 Hamad M. Alkhoori , Akhlesh Lakhtakia , Nikolaos L. Tsitsas

An expansion of a density field or particle distribution in basis functions which solve the Poisson equation both provides an easily parallelized n-body force algorithm and simplifies perturbation theories. The expansion converges quickly…

Astrophysics · Physics 2009-10-30 Martin D. Weinberg

We study a planar magnetic Schr\"odinger operator with an Aharonov-Bohm vector potential, under Neumann boundary conditions. Through a gauge transformation, the corresponding eigenvalue problem can be formulated in terms of the Laplacian on…

Analysis of PDEs · Mathematics 2026-02-17 Veronica Felli , Prasun Roychowdhury , Giovanni Siclari

Inferring electromagnetic propagation characteristics within the marine atmospheric boundary layer (MABL) from data in real time is crucial for modern maritime navigation and communications. The propagation of electromagnetic waves is well…

Atmospheric and Oceanic Physics · Physics 2019-01-23 Marc Aurèle Gilles , Christopher Earls , David Bindel

In 1977 Berg & Purcell published a landmark paper entitled "Physics of Chemoreception" which examined how a bacterium can sense a chemical attractant in the fluid surrounding it. At small scales the attractant molecules move by Brownian…

Analysis of PDEs · Mathematics 2017-07-18 Andrew J. Bernoff , Alan E. Lindsay

A new discretization approach is presented for the simulation of flow in complex poro-fractured media described by means of the Discrete Fracture and Matrix Model. The method is based on the numerical optimization of a properly defined…

Numerical Analysis · Mathematics 2020-04-10 Stefano Berrone , Alessandro D'Auria , Stefano Scialo'

The Dirac-Morse problem are investigated within the framework of an approximation to the term proportional to $1/r^2$ in the view of the position-dependent mass formalism. The energy eigenvalues and corresponding wave functions are obtained…

Quantum Physics · Physics 2012-04-16 Altug Arda , Ramazan Sever , Cevdet Tezcan , Huseyin Akcay

An unsteady problem is considered for a space-fractional diffusion equation in a bounded domain. A first-order evolutionary equation containing a fractional power of an elliptic operator of second order is studied for general boundary…

Numerical Analysis · Computer Science 2014-12-19 Petr N. Vabishchevich