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Cells and organisms follow aligned structures in their environment, a process that can generate persistent migration paths. Kinetic transport equations are a popular modelling tool for describing biological movements at the mesoscopic…

Cell Behavior · Quantitative Biology 2021-01-13 Nadia Loy , Thomas Hillen , Kevin John Painter

We propose a new model to describe diffusion processes within active deformable media. Our general theoretical framework is based on physical and mathematical considerations, and it suggests to use diffusion tensors directly coupled to…

Tissues and Organs · Quantitative Biology 2021-03-03 Christian Cherubini , Simonetta Filippi , Alessio Gizzi , Ricardo Ruiz-Baier

Riemannian diffusion models draw inspiration from standard Euclidean space diffusion models to learn distributions on general manifolds. Unfortunately, the additional geometric complexity renders the diffusion transition term inexpressible…

Machine Learning · Computer Science 2023-11-01 Aaron Lou , Minkai Xu , Stefano Ermon

We show theoretically that an imposed uniaxial anisotropy leads to new universality classes for the dynamics of active particles suspended in a viscous fluid. In the homogeneous state, their concentration relaxes superdiffusively, stirred…

Soft Condensed Matter · Physics 2026-03-26 Lokrshi Prawar Dadhichi , Suvendra K. Sahoo , K. Vijay Kumar , Sriram Ramaswamy

Anisotropic Diffusion is widely used for noise reduction with simultaneous preservation of vascular structures in maximum intensity projected (MIP) angiograms. However, extension to minimum intensity projected (mIP) venograms in…

Computer Vision and Pattern Recognition · Computer Science 2015-01-15 P. K. Akshara , J. S. Paul

Diffusivity is a key quantity in describing velocity fluctuations in granular materials. These fluctuations are the basis of many thermodynamic and hydrodynamic models which aim to provide a statistical description of granular systems. We…

Soft Condensed Matter · Physics 2009-11-10 Brian Utter , R. P. Behringer

In many situations, the combined effect of advection and diffusion greatly increases the rate of convergence to equilibrium -- a phenomenon known as enhanced dissipation. Here we study the situation where the advecting velocity field…

Dynamical Systems · Mathematics 2025-02-11 William Cooperman , Gautam Iyer , Seungjae Son

We study the Langevin diffusion of a relativistic heavy quark in anisotropic strongly coupled theories in the local limit. Firstly, we use the axion space-dependent deformed anisotropic N=4 sYM, where the geometry anisotropy is always…

High Energy Physics - Theory · Physics 2015-03-25 Dimitrios Giataganas , Hesam Soltanpanahi

Passive scalar mixing (metals, molecules, etc.) in the turbulent interstellar medium (ISM) is critical for abundance patterns of stars and clusters, galaxy and star formation, and cooling from the circumgalactic medium. However, the…

Astrophysics of Galaxies · Physics 2017-03-22 Matthew J. Colbrook , Xiangcheng Ma , Philip F. Hopkins , Jonathan Squire

Low-dimensional excitonic materials have inspired much interest owing to their novel physical and technological prospects. In particular, those with strong in-plane anisotropy are among the most intriguing but short of general analyses. We…

Mesoscale and Nanoscale Physics · Physics 2021-07-28 Chern Chuang , Jianshu Cao

Explicit examples of scalar enhanced diffusion due to resonances between different transport mechanisms are presented. Their signature is provided by the sharp and narrow peaks observed in the effective diffusivity coefficients and, in the…

chao-dyn · Physics 2009-10-31 P. Castiglione , A. Crisanti , A. Mazzino , M. Vergassola , A. Vulpiani

The properties of liquid water are known to change drastically in confined geometries. A most interesting and intriguing phenomenon is that the diffusion of water is found to be strongly enhanced by the proximity of a hydrophobic confining…

Soft Condensed Matter · Physics 2024-12-06 Lorenzo Agosta , Kersti Hermansson , Mikhail Dzugutov

The reversible reactions like A+B <-> C in the many-component diffusive system affect the diffusive properties of the constituents. The effective conjugation of irreversible processes of different dimensionality takes place due to the…

Other Condensed Matter · Physics 2007-05-23 Serge Shpyrko , Vladimir M. Sysoev

We provide examples of initial data which saturate the enhanced diffusion rates proved for general shear flows which are H\"{o}lder regular or Lipschitz continuous with critical points, and for regular circular flows, establishing the…

Analysis of PDEs · Mathematics 2019-11-25 Michele Coti Zelati , Theodore D. Drivas

We consider elliptic diffusion problems with a random anisotropic diffusion coefficient, where, in a notable direction given by a random vector field, the diffusion strength differs from the diffusion strength perpendicular to this notable…

Numerical Analysis · Mathematics 2018-02-13 Helmut Harbrecht , Marc Schmidlin

We explore the macroscopic consequences of lattice anisotropy for Diffusion Limited Aggregation (DLA) in three dimensions. Simple cubic and BCC lattice growths are shown to approach universal asymptotic states in a coherent fashion, and the…

Statistical Mechanics · Physics 2007-05-23 Nicholas R. Goold , Ellak Somfai , Robin C. Ball

This work presents a generalized physical interpretation of unconventional dispersion asymmetries associated moving elastic solids. By shifting the notion from systems with time-variant material fields to physically traveling materials, the…

Applied Physics · Physics 2019-01-15 M. A. Attarzadeh , M. Nouh

Diffusion problems with anisotropic features arise in the various areas of science and engineering fields. As a Lagrangian mesh-less method, SPH has a special advantage in addressing the diffusion problems due to the the benefit of dealing…

Computational Engineering, Finance, and Science · Computer Science 2024-10-14 Xiaojing Tang , Oskar Haidn , Xiangyu Hu

External flows, such as shear flow, add directional biases to particle motion, introducing anisotropic behavior into the system. Here, we explore the non-equilibrium dynamics that emerge from the interplay between linear shear flow and…

Statistical Mechanics · Physics 2024-10-15 Iman Abdoli , Kristian Stølevik Olsen , Hartmut Löwen

Do contemporary diffusion models preserve the class geometry of hyperspherical data? Standard diffusion models rely on isotropic Gaussian noise in the forward process, inherently favoring Euclidean spaces. However, many real-world problems…

Computer Vision and Pattern Recognition · Computer Science 2025-06-13 Muskan Dosi , Chiranjeev Chiranjeev , Kartik Thakral , Mayank Vatsa , Richa Singh