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Strong Alfv\'enic turbulence develops eddy-like motions perpendicular to the local direction of magnetic fields. This local alignment induces velocity gradients perpendicular to the local direction of the magnetic field. We use this fact to…

Astrophysics of Galaxies · Physics 2017-01-25 Diego F. González-Casanova , A. Lazarian

The atomic-to-molecular (HI-to-H$_2$) transition in photodissociation regions (PDRs) has been investigated over the last several decades through analytic and numerical modeling. However, classical PDR models typically assume uniform density…

Astrophysics of Galaxies · Physics 2021-01-06 Yue Hu , A. Lazarian , Shmuel Bialy

Radio-wave scintillation observations reveal a nearly Kolmogorov spectrum of density fluctuations in the ionized interstellar medium. Although this density spectrum is suggestive of turbulence, no theory relevant to its interpretation…

Astrophysics · Physics 2009-11-06 Yoram Lithwick , Peter Goldreich

The role of turbulence in various astrophysical settings is reviewed. Among the differences to laboratory and atmospheric turbulence we highlight the ubiquitous presence of magnetic fields that are generally produced and maintained by…

Solar and Stellar Astrophysics · Physics 2015-03-13 Axel Brandenburg , Aake Nordlund

For more than five decades, a notable spread in the low frequencies of velocity and temperature spectra, scaled using inertial subrange properties and Monin-Obukhov similarity theory, has been observed in unstable stratification. A large…

Fluid Dynamics · Physics 2023-11-08 Claudine Charrondière , Ivana Stiperski

The magnetorotational instability is thought to play an important role in enabling accretion in sufficiently ionized astrophysical disks. The rate at which MRI-driven turbulence transports angular momentum is related to both the strength of…

Solar and Stellar Astrophysics · Physics 2015-10-26 Gareth C. Murphy , Martin E. Pessah

The question of the relative importance of coherent structures and waves has for a long time attracted a great deal of interest in astrophysical plasma turbulence research, with a more recent focus on kinetic scale dynamics. Here we utilize…

Plasma Physics · Physics 2019-08-30 D. Groselj , C. H. K. Chen , A. Mallet , R. Samtaney , K. Schneider , F. Jenko

This study proceeds with the development of the technique employing velocity gradients that were identified in (\cite{GL17}, henceforth GL17) as a means of probing magnetic field in interstellar media. We demonstrate a number of practical…

Astrophysics of Galaxies · Physics 2017-05-25 Ka Ho Yuen , A. Lazarian

We employ a generalization of the She & Leveque model to study velocity scaling relations based on our simulations of thermal instability--induced turbulence. Being a by-product of the interstellar phase transition, such multiphase…

Astrophysics · Physics 2009-11-10 Alexei G. Kritsuk , Michael L. Norman

High precision cosmology with weak gravitational lensing requires a precise measure of the Point Spread Function across the imaging data where the accuracy to which high spatial frequency variation can be modelled is limited by the stellar…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-30 Catherine Heymans , Barnaby Rowe , Henk Hoekstra , Lance Miller , Thomas Erben , Thomas Kitching , Ludovic Van Waerbeke

When very small particles are suspended in a fluid in motion, they tend to follow the flow. How such tracer particles are mixed, transported, and dispersed by turbulent flow has been successfully described by statistical models. Heavy…

Fluid Dynamics · Physics 2023-12-21 J. Bec , K. Gustavsson , B. Mehlig

We study the scaling behaviors in the wind velocity time series collected at the atmospheric surface layer and compare them with two commonly used cascade models, the truncated stable distribution and the log-normal model. Results show that…

Fluid Dynamics · Physics 2012-12-03 Lei Liu , Fei Hu

We analyze the deviations from Maxwell-Boltzmann statistics found in recent experiments studying velocity distributions in two-dimensional granular gases driven into a non-equilibrium stationary state by a strong vertical vibration. We show…

Statistical Mechanics · Physics 2009-11-07 Alain Barrat , Emmanuel Trizac

We consider turbulent synchrotron emitting media that also exhibits Faraday rotation and provide a statistical description of synchrotron polarization fluctuations. In particular, we consider these fluctuations as a function of the spatial…

Astrophysics of Galaxies · Physics 2016-03-09 Alex Lazarian , Dmitri Pogosyan

The nonlinear transfer rate of the total energy (transfer rate of kinetic energy + transfer rate due to the work done by the magnetization) for an incompressible turbulent ferrofluid system is studied under the assumption of statistical…

Fluid Dynamics · Physics 2024-05-08 Sukhdev Mouraya , Nandita Pan , Supratik Banerjee

The small-scale statistical properties of velocity circulation in classical homogeneous and isotropic turbulent flows are assessed through a modeling framework that brings together the multiplicative cascade and the structural descriptions…

Fluid Dynamics · Physics 2022-08-17 Luca Moriconi , Rodrigo M. Pereira , Victor J. Valadão

Due to the inevitable accumulation of the observed information in the direction of the line of sight, it is difficult to measure the local magnetic field of MHD turbulence. However, the correct understanding of the local magnetic field is a…

High Energy Astrophysical Phenomena · Physics 2020-05-27 Jian-Fu Zhang , Ke Hu , Jungyeon Cho , Alex Lazarian

Motivated by previous work on kinetic energy cascades in the ocean and atmosphere, we develop a spatio-temporal spectral transfer tool that can be used to study scales of variability in generalized dynamical systems. In particular, we use…

Magnetic reconnection is a process that changes magnetic field topology in highly conducting fluids. Within the standard Sweet-Parker model, this process would be too slow to explain observations (e.g. solar flares). In reality, the process…

Astrophysics of Galaxies · Physics 2017-04-05 Grzegorz Kowal , Diego A. Falceta-Gonçalves , Alex Lazarian , Ethan T. Vishniac

X-ray observations of the hot gas filling the intra-cluster medium provide a wealth of information on the dynamics of clusters of galaxies. The global equilibrium of the ICM is believed to be partially ensured by non-thermal pressure…

Cosmology and Nongalactic Astrophysics · Physics 2019-09-25 E. Cucchetti , N. Clerc , E. Pointecouteau , P. Peille , F. Pajot