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Supersonic turbulence occurs in many environments, particularly in astrophysics. In the crucial case of isothermal turbulence, the probability density function (PDF) of the logarithmic density, $s$, is well measured, but a theoretical…

Astrophysics of Galaxies · Physics 2024-10-31 Evan Scannapieco , Liubin Pan , Edward Buie , Marcus Brüggen

We apply the methods of Field Theory to study the turbulent regimes of statistical systems. First we show how one can find their probability densities. For the case of the theory of wave turbulence with four-wave interaction we calculate…

High Energy Physics - Theory · Physics 2009-10-28 V. Gurarie

The point spread function (PSF) is fundamental to any type of microscopy, most importantly so for single-molecule localization techniques, where the exact PSF shape is crucial for precise molecule localization at the nanoscale. However,…

Diffusing-Wave Spectroscopy (DWS) treats the transport of photons through turbid samples as a diffusion process, thereby making it possible to extract the dynamics of scatterers from measured correlation functions. The analysis of DWS data…

Soft Condensed Matter · Physics 2017-12-27 Zahra Fahimi , Frank Aangenendt , Panayiotis Voudouris , Johan Mattson , Hans M. Wyss

This paper is concerned with the processes of spatial propagation and penetration of turbulence from the regions where it is locally excited into initially laminar regions. The phenomenon has come to be known as "turbulence spreading" and…

Pattern Formation and Solitons · Physics 2023-12-22 Alexander V. Milovanov , Jens Juul Rasmussen

In this paper, a novel gamma-shadowed two-ray with diffuse power (GS-TWDP) composite fading model is proposed. The model is intended for modeling propagation in the emerging wireless networks working at millimeter wave (mmWave) frequencies,…

Signal Processing · Electrical Eng. & Systems 2022-03-07 Pamela Njemcevic , Almir Maric

The statistical properties of interstellar turbulence are studied by means of three-dimensional high-resolution HD and MHD simulations of a SN-driven ISM. It is found that the longitudinal and transverse turbulent length scales have time…

Astrophysics · Physics 2017-08-23 Miguel A. de Avillez , Dieter Breitschwerdt

We propose a theoretical framework where the dissipative structures of turbulence emerge from microscopic path uncertainty. By modeling fluid parcels as stochastic tracers governed by the Schr\"odinger Bridge (SB) variational principle, we…

Fluid Dynamics · Physics 2025-12-04 Marcial Sanchis-Agudo , Ricardo Vinuesa

In-situ spacecraft observations recently suggested that the transport of energetic particles accelerated at heliospheric shocks can be anomalous, i.e. the mean square displacement can grow non-linearly in time. In particular, a new analysis…

Solar and Stellar Astrophysics · Physics 2015-06-01 Silvia Perri , Gaetano Zimbardo , Frederic Effenberger , Horst Fichtner

Free-space optical (FSO) transmission enables fast, secure, and efficient next-generation communications with abundant spectrum resources. However, atmospheric turbulence, pointing errors, path loss, and atmospheric loss induce random…

Signal Processing · Electrical Eng. & Systems 2025-11-25 Jingtian Liu , Xiongwei Yang , Yi Wei , Jianjun Yu , Feng Zhao

The transport equation of active motion is generalised to consider time-fractional dynamics for describing the anomalous diffusion of self-propelled particles observed in many different systems. In the present study, we consider an…

Statistical Mechanics · Physics 2023-10-27 Francisco J. Sevilla , Guillermo Chacón-Acosta , Trifce Sandev

The radio continuum spectra of pulsars (PSRs) exhibit a wide variety of shapes, that are interpreted as pure and broken power laws, power laws with turnovers or cut-offs, and logarithmic-parabolic profiles. A notable fraction of these have…

Astrophysics of Galaxies · Physics 2025-11-24 Mario G. Abadi , Gabriela Castelletti , Namir E. Kassim

Radial velocity fluctuations on the plane of the sky are a powerful tool for studying the turbulent dynamics of emission line regions. We conduct a systematic statistical analysis of the H alpha velocity field for a diverse sample of 9 H II…

Astrophysics of Galaxies · Physics 2023-06-14 J. García-Vázquez , William J. Henney , H. O. Castañeda

We develop a visibility based power spectrum estimator to probe the power spectrum directly from the interferometric observations and also estimate the errors in it. A numerical simulation of synthetic observations is also performed to…

Astrophysics of Galaxies · Physics 2011-02-23 Prasun Dutta

Perturbation Theory (PT) applied to a cosmological density field with Gaussian initial fluctuations suggests a specific hierarchy for the correlation functions when the variance is small. In particular quantitative predictions have been…

Astrophysics · Physics 2009-10-30 D. Munshi , F. Bernardeau , A. L. Melott , R. Schaeffer

The velocity fluctuations for point vortex models are studied for the {\alpha}-turbulence equations, which are characterized by a fractional Laplacian relation between active scalar and the streamfunction. In particular, we focus on the…

Fluid Dynamics · Physics 2019-09-11 Giovanni Conti , Gualtiero Badin

We consider the efficiency of turbulence, a dimensionless parameter that characterises the fraction of the input energy stored into a turbulent flow field. We first show that the inverse of the efficiency provides an upper bound for the…

Fluid Dynamics · Physics 2025-08-11 A Lopez , A Barral , G Costa , Q Pikeroen , V Shukla , Bérengère Dubrulle

Driven by the need for describing and understanding wave propagation in structural materials and components, several analytical, numerical, and experimental techniques have been developed to obtain dispersion curves. Accurate…

Signal Processing · Electrical Eng. & Systems 2020-02-26 Mohammad I. Albakri , Vijaya V. N. Sriram Malladi , Serkan Gugercin , Pablo A. Tarazaga

We report the experimental characterization of free-surface deformations generated by three-dimensional homogeneous and isotropic turbulence. Using Fourier transform profilometry in a jet-forced turbulent tank, we perform spatiotemporal…

Fluid Dynamics · Physics 2026-05-14 Michaël Berhanu , Eric Falcon

HI line widths are typically interpreted as a measure of ISM turbulence, which is potentially driven by star formation. In an effort to better understand the possible connections between line widths and star formation, we have characterized…

Astrophysics of Galaxies · Physics 2015-06-12 Adrienne M. Stilp , Julianne J. Dalcanton , Steven R. Warren , Evan Skillman , Juergen Ott , Baerbel Koribalski