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Related papers: Metadiffusion

200 papers

Calculations are presented detailing the gravitational lens diffraction due to the steep brightness gradient of the limb of a stellar source. The lensing case studied is the fold caustic crossing. The limb diffraction signal greatly exceeds…

Astrophysics · Physics 2008-11-26 S. A. Zabel , J. B. Peterson

Theoretical and numerical wave propagation analysis of an oscillating electric dipole is presented. The results show that upon creation at the source, both the longitudinal electric and transverse magnetic fields propagate superluminally…

General Physics · Physics 2007-05-23 William D. Walker

Stochasticity of magnetic field lines is important for particle transport properties. Magnetic field lines separate faster than diffusively in turbulent plasma, which is called superdiffusion. We discovered that this superdiffusion is…

High Energy Astrophysical Phenomena · Physics 2015-06-15 Andrey Beresnyak

Cosmic-ray scattering on magnetic turbulence leads to spatial diffusive propagation; if the scattering medium is moving, this will inevitably also cause changes in the momentum of the particles, so-called diffusive reacceleration. This can…

High Energy Astrophysical Phenomena · Physics 2015-08-12 Luke O'C. Drury , Andrew W. Strong

Expanding our previous work on turbulent whirls [1] we have uncovered a similarity within the similarity shared by intense vortices. Using the new information we compress the tangential velocity profiles of a diverse set of vortices into…

Astrophysics of Galaxies · Physics 2010-12-08 Georgios H. Vatistas

Fast particles diffusing along magnetic field lines in a turbulent plasma can diffuse through and then return to the same eddy many times before the eddy is randomized in the turbulent flow. This leads to an enhancement of particle…

Astrophysics · Physics 2009-11-10 Benjamin D. G. Chandran , Jason L. Maron

Frequency-dependent gravitational lens effects are found for trajectories of electromagnetic rays passing through a distribution of plasma near a massive object. Ray propagation through plasma adds extra terms to the equations of motion…

General Relativity and Quantum Cosmology · Physics 2016-11-02 Adam Rogers

On long enough timescales, chaotic diffusion has the potential to significantly alter the appearance of a dynamical system. The solar system is no exception: diffusive processes take part in the transportation of small bodies and provide…

Earth and Planetary Astrophysics · Physics 2023-06-14 Emese Kővári , Emese Forgács-Dajka , Tamás Kovács , Csaba Kiss , Zsolt Sándor

Similar to the light, gravitational waves traveling in multiple paths may arrive at the same location if there is a gravitational lens on their way. Apart from the magnification of the amplitudes and the time delay between the gravitational…

General Relativity and Quantum Cosmology · Physics 2019-09-19 Shaoqi Hou , Xi-Long Fan , Zong-Hong Zhu

Peculiar velocities change the expansion rate of any observer moving relative to the smooth Hubble flow. As a result, observers in a galaxy like our Milky Way can experience accelerated expansion within a globally decelerating universe,…

Cosmology and Nongalactic Astrophysics · Physics 2011-09-29 Christos G. Tsagas

The atmosphere is a nonlinear stratified fluid in which internal gravity waves are present. These waves interact with the flow, resulting in wave turbulence that displays important differences with the turbulence observed in isotropic and…

Fluid Dynamics · Physics 2015-06-23 P. Clark di Leoni , P. D. Mininni

We use confocal microscopy to directly visualize the spatial fluctuations in fluid flow through a three-dimensional porous medium. We find that the velocity magnitudes and the velocity components both along and transverse to the imposed…

Soft Condensed Matter · Physics 2013-08-07 Sujit S. Datta , Harry Chiang , T. S. Ramakrishnan , David A. Weitz

Turbulence acting on mixes of gas and particles generally evenly diffuses the latter through the former. However, in the presence of background gas temperature gradients a phenomenon known as turbulent thermal diffusion appears as a…

Earth and Planetary Astrophysics · Physics 2016-01-27 Alexander Hubbard

Perturbative partial-wave amplitudes diverge in cases with a massless exchanged particle in the $t$-channel. We argue that the divergence is an artifact of perturbation theory and give a prescription for the all-orders correction factor…

High Energy Physics - Phenomenology · Physics 2025-10-13 Marta Fuentes Zamoro , Benjamín Grinstein , Pablo Quílez

Galaxies are huge physical systems having dimensions of many tens of thousands of light years. Thus any change at the galactic center will be noticed at the rim only tens of thousands of years later. Those retardation effects seems to be…

General Physics · Physics 2025-05-27 Asher Yahalom

We study the diffusion phenomena on the negatively curved surface made up of congruent heptagons. Unlike the usual two-dimensional plane, this structure makes the boundary increase exponentially with the distance from the center, and hence…

Statistical Mechanics · Physics 2008-07-15 Seung Ki Baek , Su Do Yi , Beom Jun Kim

We carry out an extended analytic study of how the tilt and faster-than-radial expansion from a magnetic field affect the mass flux and flow speed of a line-driven stellar wind. A key motivation is to reconcile results of numerical MHD…

Astrophysics · Physics 2009-11-10 Stan Owocki , Asif ud-Doula

Gravitational lensing is most often used as a tool to investigate the distribution of (dark) matter in the universe, but, if the mass distribution is known a priori, it becomes, at least in principle, a powerful probe of gravity itself.…

Astrophysics · Physics 2009-11-06 Daniel J. Mortlock , Edwin L. Turner

Temperate terrestrial planets orbiting low-mass stars are subject to strong tidal forces. The effects of gravitational tides on the solid planet and that of atmospheric thermal tides have been studied, but the direct impact of gravitational…

Earth and Planetary Astrophysics · Physics 2022-07-19 Thomas Navarro , Timothy M. Merlis , Nicolas B. Cowan , Natalya Gomez

It is known that a relative translational motion between the deflector and the observer affects gravitational lensing. In this paper, a lens equation is obtained to describe such effects on actual lensing observables. Results can be easily…

Astrophysics · Physics 2008-11-26 M. Sereno