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Related papers: Solutions of the buoyancy-drag equation with a tim…

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We present a new hydrodynamic model consisting of the pressureless Euler equations and the isentropic compressible Navier-Stokes equations where the coupling of two systems is through the drag force. This coupled system can be derived, in…

Analysis of PDEs · Mathematics 2016-04-19 Young-Pil Choi , Bongsuk Kwon

Following the idea that dissipation in turbulence at high Reynolds number is by events singular in space-time and described by solutions of the inviscid Euler equations, we draw the conclusion that in such flows scaling laws should depend…

Fluid Dynamics · Physics 2020-01-01 Yves Pomeau , Martine Le Berre

We present a new derivation of the equations governing the oscillations of slowly rotating relativistic stars. Previous investigations have been mostly carried out in the Regge-Wheeler gauge. However, in this gauge the process of…

General Relativity and Quantum Cosmology · Physics 2009-11-07 Johannes Ruoff , Adamantios Stavridis , Kostas D. Kokkotas

We propose an experimental study of adaptive time-stepping methods for efficient modeling of the aggregation-fragmentation kinetics. Precise modeling of this phenomena usually requires utilization of the large systems of nonlinear ordinary…

Numerical Analysis · Mathematics 2025-01-20 Sergey A. Matveev , Viktor Zhilin , Alexander P. Smirnov

The rate of strong convergence is investigated for an approximation scheme for a class of stochastic differential equations driven by a time-changed Brownian motion, where the random time changes $(E_t)_{t\ge 0}$ considered include the…

Probability · Mathematics 2020-03-02 Sixian Jin , Kei Kobayashi

In this paper, we consider the compressible Euler equations with time-dependent damping \frac{\a}{(1+t)^\lambda}u in one space dimension. By constructing 'decoupled' Riccati type equations for smooth solutions, we provide some sufficient…

Analysis of PDEs · Mathematics 2020-08-19 Ying Sui , Huimin Yu

We apply Maxwell and Cattaneo's relaxation approaches to the analysis of strong shockwaves in a two-dimensional viscous heat-conducting fluid. Good agreement results for reasonable values of Maxwell's relaxation times. Instability results…

Fluid Dynamics · Physics 2011-03-09 Francisco J. Uribe , Wm. G. Hoover , Carol G. Hoover

We introduce a new class of quantum models with time-dependent Hamiltonians of a special scaling form. By using a couple of time-dependent unitary transformations, the time evolution of these models is expressed in terms of related systems…

Quantum Physics · Physics 2009-11-07 L. Samaj

Biadjoint scalar field theories appear in the study of scattering amplitudes and classical solutions in gauge, gravity and related theories. In this paper, we present new exact solutions of biadjoint scalar field theory, showing that…

High Energy Physics - Theory · Physics 2025-02-04 Kymani Armstrong-Williams , Chris D. White

We construct Lewis-Riesenfeld invariants from two dimensional point transformations for two oscillators that are coupled to each other in space in a PT-symmetrical and time-dependent fashion. The non-Hermitian Hamiltonian of the model is…

Quantum Physics · Physics 2022-12-28 Andreas Fring , Rebecca Tenney

We consider a charged particle driven by a time-dependent flux threading a quantum ring. The dynamics of the charged particle is investigated using classical treatment, Fourier expansion technique, time-evolution method, and…

Mesoscale and Nanoscale Physics · Physics 2008-07-29 Pi-Gang Luan , Chi-Shung Tang

We derive analytical formulas for the wake and wave drag of a disturbance moving arbitrarily at the air-water interface. We show that, provided a constant velocity is reached in finite time, the unsteady surface displacement converges to…

Fluid Dynamics · Physics 2024-04-05 Lucas Gierczak , Assil Fadle , Maxence Arutkin , Elie Raphaël , Michael Benzaquen

The 1D bump-on-tail problem is studied in order to determine the influence of drag on quasi-steady solutions near marginal stability ($1-\gamma_d/\gamma_L\ll 1$) when effective collisions are much larger than the instability growth rate…

Plasma Physics · Physics 2023-02-10 J. B. Lestz , V. N. Duarte

We generalize Wheeler-Feynman electrodynamics with a variational boundary-value problem with past and future boundary segments that can include velocity discontinuity points. Critical-point trajectories must satisfy the Euler-Lagrange…

Classical Physics · Physics 2019-04-17 Daniel Câmara de Souza , Jayme De Luca

Highly localized explicit solutions to multidimensional wave and Klein--Gordon--Fock equations are presented. Their Fourier transform is also found explicitly. Solutions depend on a set of parameters, and demonstrate astigmatic properties.…

Mathematical Physics · Physics 2015-06-29 Ignat V. Fialkovsky , Maria V. Perel , Alexander B. Plachenov

The two-fluid (ions and electrons) plasma Richtmyer-Meshkov instability of a cylindrical light/heavy density interface is numerically investigated without an initial magnetic field. Varying the Debye length scale, we examine the effects of…

Plasma Physics · Physics 2020-11-25 Y. Li , R. Samtaney , D. Bond , V. Wheatley

For solution $u(x,t)$ to degenearte parabolic equations in a bounded domain $\Omega$ with homogenous boundary condition, we consider backward problems in time: determine $u(\cdot,t_0)$ in $\Omega$ by $u(\cdot,T)$, where $t$ is the time…

Analysis of PDEs · Mathematics 2023-05-02 Piermarco Cannarsa , Masahiro Yamamoto

We study the resonant prescribed T-curvature problem on a compact 4-dimensional Riemannian manifold with boundary. We derive sharp energy and gradient estimates of the associated Euler-Lagrange functional to characterize the critical points…

Differential Geometry · Mathematics 2021-07-28 Cheikh Birahim Ndiaye

In this paper, we consider an autonomous semi-dynamical system driven by semilinear time-nonlocal evolution equations, these type equations are used to describe the Rayleigh-Stokes problem for a non-Newtonain fluid to a generalized second…

Dynamical Systems · Mathematics 2026-05-20 Li Peng , Lin Deng , Jia Wei He

We rigorously study the long time dynamics of solitary wave solutions of the nonlinear Schr\"odinger equation in {\it time-dependent} external potentials. To set the stage, we first establish the well-posedness of the Cauchy problem for a…

Mathematical Physics · Physics 2009-11-13 Walid K. Abou Salem