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Two-fluid plasma flow equations describe the flow of ions and electrons with different densities, velocities, and pressures. We consider the ideal plasma flow i.e. we ignore viscous, resistive, and collision effects. The resulting system of…

Numerical Analysis · Mathematics 2024-09-25 Jaya Agnihotri , Deepak Bhoriya , Harish Kumar , Praveen Chandrashekhar , Dinshaw S. Balsara

We report on the application of an evolutionary algorithm (EA) to enhance performance of an ultra-cold quantum gas experiment. The production of a $^{87}$Rubidium Bose-Einstein condensate (BEC) can be divided into fundamental cooling steps,…

We introduce an auxiliary-particle field theory to treat the non-Markovian dynamics of driven-dissipative quantum systems of the Jaynes-Cummings type. It assigns an individual quantum field to each reservoir state and provides an analytic,…

Quantum Gases · Physics 2024-03-05 Tim Bode , Michael Kajan , Francisco Meirinhos , Johann Kroha

Central finite difference schemes have long been avoided in the context of two-phase flows for the advection of the phase indicator function due to numerical overshoots and undershoots associated with their dispersion errors. We will show…

Fluid Dynamics · Physics 2019-12-23 Shahab Mirjalili , Christopher B. Ivey , Ali Mani

An abstract 2nd-order evolution equation or inclusion is discretised in time in such a way that the energy is conserved at least in qualified cases, typically in the cases when the governing energy is component-wise quadratic or…

Numerical Analysis · Mathematics 2016-06-01 Tomas Roubicek , Christos G. Panagiotopoulos

Modeling transition-continuum hypersonic flows poses significant challenges due to thermodynamic nonequilibrium and the associated breakdown of the continuum assumption. Standard continuum models such as the Navier-Stokes equations are…

Fluid Dynamics · Physics 2025-06-18 Mikolaj Kryger , Jonathan F. MacArt

We revisit the problem of the reduction of the three-dimensional (3D) dynamics of Bose-Einstein condensates, under the action of strong confinement in one direction ($z$), to a 2D mean-field equation. We address this problem for the…

Quantum Gases · Physics 2020-10-14 Mateus C. P. dos Santos , Boris A. Malomed , Wesley B. Cardoso

Dilute Bose gases, cooled down to low temperatures below the Bose-Einstein condensation temperature, form coherent ensembles described by the Gross-Pitaevskii equation. Stationary solutions to the latter are topological coherent modes. The…

Mesoscale and Nanoscale Physics · Physics 2009-11-11 V. I. Yukalov , E. P. Yukalova

The aim of the present review is to introduce the reader to some of the physical notions and of the mathematical methods that are relevant to the study of nonlinear waves in Bose-Einstein Condensates (BECs). Upon introducing the general…

Other Condensed Matter · Physics 2010-12-10 R. Carretero-Gonzalez , D. J. Frantzeskakis , P. G. Kevrekidis

We maximize the production of biogas in a gradostat at steady state. The physical decision variables are the water, substrate, and biomass entering each tank and the flows through the interconnecting pipes. Our main technical focus is the…

Optimization and Control · Mathematics 2021-02-04 Josh Taylor , Alain Rapaport

This work is concerned with the construction and analysis of structure-preserving Galerkin methods for computing the dynamics of rotating Bose-Einstein condensate (BEC) based on the Gross-Pitaevskii equation with angular momentum rotation.…

Numerical Analysis · Mathematics 2024-05-28 Meng Li , Junjun Wang , Zhen Guan , Zhijie Du

We present variational calculations using a Gaussian trial function to calculate the ground state of the Gross-Pitaevskii equation and to describe the dynamics of the quasi-two-dimensional solitons in dipolar Bose-Einstein condensates.…

Quantum Gases · Physics 2011-05-05 Rüdiger Eichler , Jörg Main , Günter Wunner

Recent advances in molecular cooling have enabled the realization of strongly dipolar Bose-Einstein condensates (BECs) of molecules, and BECs of many different molecular species may become experimentally accessible in the near future. Here,…

We propose a new class of finite element approximations to ideal compressible magnetohydrodynamic equations in smooth regime. Following variational approximations developed for fluid models in the last decade, our discretizations are built…

Numerical Analysis · Mathematics 2024-02-29 Valentin Carlier , Martin Campos-Pinto

The equality between dissipation and energy drop is a structural property of gradient-flow dynamics. The classical implicit Euler scheme fails to reproduce this equality at the discrete level. We discuss two modifications of the Euler…

Numerical Analysis · Mathematics 2019-08-28 Ansgar Jüngel , Ulisse Stefanelli , Lara Trussardi

A conservative primitive variable discrete exterior calculus (DEC) discretization of the Navier-Stokes equations is performed. An existing DEC method (Mohamed, M. S., Hirani, A. N., Samtaney, R. (2016). Discrete exterior calculus…

Fluid Dynamics · Physics 2021-02-24 Pankaj Jagad , Abdullah Abukhwejah , Mamdouh Mohamed , Ravi Samtaney

To capture the dynamics of macroscopic non-relativistic fluids consisting of very many atoms, it is typically sufficient to truncate the gradient expansion at order zero, leading to ideal fluid dynamics, or at order one, leading to the…

Quantum Gases · Physics 2024-08-13 Lars H. Heyen , Giuliano Giacalone , Stefan Floerchinger

We consider the approximation of initial/boundary value problems involving, possibly high-dimensional, dissipative evolution partial differential equations (PDEs) using a deep neural network framework. More specifically, we first propose…

Numerical Analysis · Mathematics 2022-06-02 Emmanuil H. Georgoulis , Michail Loulakis , Asterios Tsiourvas

A new algebraic Bethe ansatz scheme is proposed to diagonalise classes of integrable models relevant to the description of Bose-Einstein condensates in dilute alkali gases. This is achieved by introducing the notion of Z-graded…

Statistical Mechanics · Physics 2009-11-07 H. -Q. Zhou , J. Links , M. D. Gould , R. H. McKenzie

We introduce improved Reduced Order Models (ROM) for convection-dominated flows. These non-linear closure models are inspired from successful numerical stabilization techniques used in Large Eddy Simulations (LES), such as Local Projection…

Numerical Analysis · Mathematics 2017-11-28 Mejdi Azaïez , Tomás Chacón Rebollo , Samuele Rubino