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Context. The frequencies, lifetimes, and eigenfunctions of solar acoustic waves are affected by turbulent convection, which is random in space and in time. Since the correlation time of solar granulation and the periods of acoustic waves…

Solar and Stellar Astrophysics · Physics 2020-11-25 P. -L. Poulier , D. Fournier , L. Gizon , T. L. Duvall

Optical beams propagating through atmospheric turbulence undergo spatiotemporal intensity fluctuations that deviate significantly from an ideal Gaussian profile. In this work, we present a unified theoretical and experimental framework for…

Optics · Physics 2026-03-10 Shouvik Sadhukhan , C. S. Narayanamurthy

On the one hand, several types of global-scale inertial modes of oscillation have been observed on the Sun. They include the equatorial Rossby modes, critical-latitude modes, and high-latitude modes. On the other hand, the columnar…

Solar and Stellar Astrophysics · Physics 2022-06-08 Yuto Bekki , Robert H. Cameron , Laurent Gizon

The last decade has seen a rapid development in asteroseismology thanks to the CoRoT and Kepler missions. With more detailed asteroseismic observations available, it is becoming possible to infer exactly how oscillations are driven and…

Solar and Stellar Astrophysics · Physics 2020-06-03 Yixiao Zhou , Martin Asplund , Remo Collet , Meridith Joyce

We study the linear evolution of small perturbations in self-gravitating fluid systems with magnetic fields. We consider wave-like perturbations to nonuniform filamentary and sheet-like hydrostatic equilibria in the presence of a uniform…

Astrophysics · Physics 2015-06-24 Curtis S. Gehman , Fred C. Adams , Richard Watkins

It has been shown that a discontinuity in the derivatives of the sound speed at the edge of the convective regions inside a star gives rise to a characteristic oscillatory signal in the frequencies of stellar oscillations. This oscillatory…

Astrophysics · Physics 2009-11-07 Anwesh Mazumdar , H. M. Antia

The prevalence of binary stars at close separations implies that many of these systems will interact or merge during the binary's lifetime. This paper presents hydrodynamic simulations of the scenario of binary coalescence through unstable…

Solar and Stellar Astrophysics · Physics 2019-05-29 Morgan MacLeod , Michelle Vick , Dong Lai , James M. Stone

It has been reported that traveling waves propagate periodically and stably in sub-excitable systems driven by noise [Phys. Rev. Lett. \textbf{88}, 138301 (2002)]. As a further investigation, here we observe different types of traveling…

Chaotic Dynamics · Physics 2008-01-17 Fen-Ni Si , Quan-Xing Liu , Jin-Zhong Zhang , Lu-Qun Zhou

This article reviews our current understanding of modelling convection dynamics in stars. Several semi-analytical time-dependent convection models have been proposed for pulsating one-dimensional stellar structures with different…

Solar and Stellar Astrophysics · Physics 2016-01-18 Günter Houdek , Marc-Antoine Dupret

We prove the unique solvability, passivity/conservativity and some regularity results of two mathematical models for acoustic wave propagation in curved, variable diameter tubular structures of finite length. The first of the models is the…

Dynamical Systems · Mathematics 2014-05-29 Atte Aalto , Teemu Lukkari , Jarmo Malinen

Modal methods are a long-standing approach to physical modelling synthesis. Extensions to nonlinear problems are possible, leading to coupled nonlinear systems of ordinary differential equations. Recent work in scalar auxiliary variable…

Sound · Computer Science 2026-03-17 Victor Zheleznov , Stefan Bilbao , Alec Wright , Simon King

We present a formalism for investigating the interaction between pmode oscillations and convection by analyzing realistic, three-dimensional simulations of the near-surface layers of the solar convection zone. By choosing suitable…

Astrophysics · Physics 2009-10-31 Å. Nordlund , R. F. Stein

In the present paper, we combine numerical and experimental approaches to study the dynamics of stable and unstable internal wave attractors. The problem is considered in a classic trapezoidal setup filled with a uniformly stratified fluid.…

Fluid Dynamics · Physics 2021-02-10 Christophe Brouzet , Ilias Sibgatullin , H Scolan , E. V. Ermanyuk , Thierry Dauxois

We consider reaction-diffusion systems with multiplicative noise on a spatial domain of dimension two or higher. The noise process is white in time, coloured in space, and invariant under translations. In the deterministic setting,…

Analysis of PDEs · Mathematics 2024-06-07 Mark van den Bosch , Hermen Jan Hupkes

The fact that fast oscillating homogeneous scalar fields behave as perfect fluids in average and their intrinsic isotropy have made these models very fruitful in cosmology. In this work we will analyse the perturbations dynamics in these…

Cosmology and Nongalactic Astrophysics · Physics 2016-03-23 J. A. R. Cembranos , A. L. Maroto , S. J. Núñez Jareño

We consider solutions in frequency bands of dispersive equations on the line defined by Fourier multipliers, these solutions being considered as wave packets. In this paper, a refinement of an existing method permitting to expand…

Analysis of PDEs · Mathematics 2020-01-30 Florent Dewez

The evolution of the amplitude of two nonlinearly interacting waves is considered, via a set of coupled nonlinear Schroedinger-type equations. The dynamical profile is determined by the wave dispersion laws (i.e. the group velocities and…

Pattern Formation and Solitons · Physics 2009-11-11 I. Kourakis , P. K. Shukla

The instability and nonlinear evolution of directional ocean waves is investigated numerically by means of simulations of the governing kinetic equation for narrow-band surface waves. Our simulation results reveal the onset of the…

Fluid Dynamics · Physics 2015-05-14 Bengt Eliasson , Padma K. Shukla

Differences between observed and theoretical eigenfrequencies of the Sun have characteristics which identify them as arising predominantly from properties of the oscillations in the vicinity of the solar surface: in the super-adiabatic,…

Recent progress in realistic simulations of solar convection have given us an unprecedented opportunity to evaluate the robustness of solar interior structures and dynamics obtained by methods of local helioseismology. We present results of…

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