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We present a scalable approach to solve a class of elliptic partial differential equation (PDE)-constrained optimization problems with bound constraints. This approach utilizes a robust full-space interior-point (IP)-Gauss-Newton…

Optimization and Control · Mathematics 2024-10-22 Tucker Hartland , Cosmin G. Petra , Noemi Petra , Jingyi Wang

In toroidally confined plasmas, the Grad-Shafranov equation, in general a non-linear PDE, describes the hydromagnetic equilibrium of the system. This equation becomes linear when the kinetic pressure is proportional to the poloidal magnetic…

Plasma Physics · Physics 2015-06-22 D. Ciro , I. L. Caldas

Self similarity allows for analytic or semi-analytic solutions to many hydrodynamics problems. Most of these solutions are one dimensional. Using linear perturbation theory, expanded around such a one-dimensional solution, we find…

High Energy Astrophysical Phenomena · Physics 2015-05-30 Re'em Sari , J. Nate Bode , Almog Yalinewich , Andrew MacFadyen

Quantum integrable systems, such as the interacting Bose gas in one dimension and the XXZ quantum spin chain, have an extensive number of local conserved quantities that endow them with exotic thermalization and transport properties. We…

Statistical Mechanics · Physics 2018-02-21 Vir B. Bulchandani , Romain Vasseur , Christoph Karrasch , Joel E. Moore

We study confined solutions of certain evolutionary partial differential equations (pde) in 1+1 space-time. The pde we study are Lie-Poisson Hamiltonian systems for quadratic Hamiltonians defined on the dual of the Lie algebra of vector…

solv-int · Physics 2007-05-23 O. B. Fringer , D. D. Holm

This paper is devoted to the study of the large time behaviour of viscosity solutions of parabolic equations with Neumann boundary conditions. This work is the sequel of [13] in which a probabilistic method was developped to show that the…

Probability · Mathematics 2015-09-18 Ying Hu , Pierre-Yves Madec

Recent advances in high-resolution imaging techniques and particle-based simulation methods have enabled the precise microscopic characterization of collective dynamics in various biological and engineered active matter systems. In…

Soft Condensed Matter · Physics 2023-02-14 Rohit Supekar , Boya Song , Alasdair Hastewell , Gary P. T. Choi , Alexander Mietke , Jörn Dunkel

We describe a computational framework for simulating suspensions of rigid particles in Newtonian Stokes flow. One central building block is a collision-resolution algorithm that overcomes the numerical constraints arising from particle…

Computational Engineering, Finance, and Science · Computer Science 2020-06-24 Wen Yan , Eduardo Corona , Dhairya Malhotra , Shravan Veerapaneni , Michael Shelley

A new method of solution is proposed for solution of the wave equation in one space dimension with continuously-varying coefficients. By considering all paths along which information arrives at a given point, the solution is expressed as an…

Analysis of PDEs · Mathematics 2019-10-11 Jithin D. George , David I. Ketcheson , Randall J. LeVeque

We present a numerical method to solve the equations of general relativistic hydrodynamics in a given external gravitational field. The method is based on a generalization of Roe's approximate Riemann solver for the non relativistic Euler…

Astrophysics · Physics 2007-05-23 Frits Eulderink , Garrelt Mellema

We develop a new numerical scheme for solving the radiative transfer equation in a spherically symmetric system. This scheme does not rely on any kind of diffusion approximation and it is accurate for optically thin, thick, and intermediate…

Instrumentation and Methods for Astrophysics · Physics 2018-05-31 Torsten Stamer , Shu-ichiro Inutsuka

In this work we introduce a novel semi-implicit structure-preserving finite-volume/finite-difference scheme for the viscous and resistive equations of magnetohydrodynamics (MHD) based on an appropriate 3-split of the governing PDE system,…

Numerical Analysis · Mathematics 2021-12-01 Francesco Fambri

A method is developed within an adaptive framework to solve quasilinear diffusion problems with internal and possibly boundary layers starting from a coarse mesh. The solution process is assumed to start on a mesh where the problem is badly…

Numerical Analysis · Mathematics 2016-02-16 Sara Pollock

The dynamics of self-gravitating fluid bodies is described by the Euler-Einstein system of partial differential equations. The break-down of well-posedness on the fluid-vacuum interface remains a challenging open problem, which is…

General Relativity and Quantum Cosmology · Physics 2020-07-17 John Ryan Westernacher-Schneider , Charalampos Markakis , Bing Jyun Tsao

Exact self-consistent particle-like solutions with spherical and/or cylindrical symmetry to the equations governing the interacting system of scalar, electromagnetic and gravitational fields have been obtained. As a particular case it is…

General Relativity and Quantum Cosmology · Physics 2010-05-27 Yu. P. Rybakov , B. Saha , G. N. Shikin

Ion transport, often described by the Poisson--Nernst--Planck (PNP) equations, is ubiquitous in electrochemical devices and many biological processes of significance. In this work, we develop conservative, positivity-preserving, energy…

Numerical Analysis · Mathematics 2020-07-15 Jie Ding , Zhongming Wang , Shenggao Zhou

We describe an extension of the Enzo code to enable fully-coupled radiation hydrodynamical simulation of inhomogeneous reionization in large $\sim (100 Mpc)^3$ cosmological volumes with thousands to millions of point sources. We solve all…

Instrumentation and Methods for Astrophysics · Physics 2015-06-16 Michael L. Norman , Daniel R. Reynolds , Geoffrey C. So , Robert P. Harkness , John H. Wise

The development of radiation hydrodynamical methods that are able to follow gas dynamics and radiative transfer self-consistently is key to the solution of many problems in numerical astrophysics. Such fluid flows are highly complex, rarely…

The density functional approach in the Kohn-Sham approximation is widely used to study properties of many-electron systems. Due to the nonlinearity of the Kohn-Sham equations, the general self-consistence searching method involves…

Materials Science · Physics 2015-05-13 D. V. Posvyanskii , A. Ya. Shul'man

In this work, we investigate the existence and uniqueness properties of a composite structure (multilayered) fluid interaction PDE system which arises in multi-physics problems, and particularly in biofluidic applications related to the…

Analysis of PDEs · Mathematics 2024-03-01 Pelin G. Geredeli