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Discrete diffusion has become a leading framework for generative modeling in various applications including language, vision, and biology. Existing convergence theory, however, exhibits fundamental limitations. KL-based analyses diverge…

Machine Learning · Computer Science 2026-05-19 Kelvin Kan , Xingjian Li , Benjamin J. Zhang , Tuhin Sahai , Stanley Osher , Markos A. Katsoulakis

Anisotropic light transport is extremely common among scattering materials, yet a comprehensive picture of how macroscopic diffusion is determined by microscopic tensor scattering coefficients is not fully established yet. In this work, we…

Our recent work identifies material surfaces in incompressible flows that extremize the transport of an arbitrary, weakly diffusive scalar field relative to neighboring surfaces. Such barriers and enhancers of transport can be located…

Fluid Dynamics · Physics 2020-06-12 George Haller , Daniel Karrasch , Florian Kogelbauer

We demonstrate a method for filtering images defined on curved surfaces embedded in 3D. Applications are noise removal and the creation of artistic effects. Our approach relies on in-surface diffusion: we formulate Weickert's edge/coherence…

Numerical Analysis · Mathematics 2014-04-08 Emma Naden , Thomas März , Colin B. Macdonald

Controllable spherical panoramic image generation holds substantial applicative potential across a variety of domains.However, it remains a challenging task due to the inherent spherical distortion and geometry characteristics, resulting in…

Computer Vision and Pattern Recognition · Computer Science 2024-03-18 Tao Wu , Xuewei Li , Zhongang Qi , Di Hu , Xintao Wang , Ying Shan , Xi Li

Enzymes have been recently proposed to have mechanical activity associated with their chemical activity. In a number of recent studies, it has been reported that enzymes undergo enhanced diffusion in the presence of their corresponding…

Biological Physics · Physics 2021-04-07 Jaime Agudo-Canalejo , Tunrayo Adeleke-Larodo , Pierre Illien , Ramin Golestanian

Depending on their mechanism of self-propulsion, active particles can exhibit a time-dependent, often periodic, propulsion velocity. The precise propulsion velocity profile determines their mean square displacement and their effective…

Soft Condensed Matter · Physics 2024-05-06 Arnau Jurado Romero , Carles Calero , Rossend Rey

This survey provides a concise yet comprehensive overview on enhanced dissipation phenomena, transitioning seamlessly from the physical principles underlying the interplay between advection and diffusion to their rigorous mathematical…

Analysis of PDEs · Mathematics 2025-02-03 Anna L. Mazzucato , Yuanyuan Feng , Camilla Nobili

Various bias-correction methods such as EXTRA, gradient tracking methods, and exact diffusion have been proposed recently to solve distributed {\em deterministic} optimization problems. These methods employ constant step-sizes and converge…

Machine Learning · Computer Science 2023-07-19 Kun Yuan , Sulaiman A. Alghunaim , Bicheng Ying , Ali H. Sayed

We report a molecular dynamics simulation investigating the dynamics of a simple liquid in the proximity to a non-interacting smooth confining wall. A strong enhancement of the liquid diffusion is observed within the layers adjacent to the…

Materials Science · Physics 2024-12-06 Lorenzo Agosta , Mikhail Dzugutov , Wim Briels , Kersti Hermansson

Diffusion is a fundamental physical phenomenon with critical applications in fields such as metallurgy, cell biology, and population dynamics. While standard diffusion is well-understood, anomalous diffusion often requires complex non-local…

Statistical Mechanics · Physics 2026-01-16 Gabriel Barreiro , Vladimir Pérez-Veloz

The main contribution of this paper is twofold: (1) Recently, Iyer, Xu, and Zlato\v{s} studied the dissipation enhancement by cellular flows based on standard advection-diffusion equations via a stochastic method. We generalize their…

Analysis of PDEs · Mathematics 2022-11-01 Yu Feng , Xiaoqian Xu

In this paper we present a method to improve the description of 0+1 dimensional boost invariant dissipative dynamics in the presence of large momentum-space anisotropies. We do this by reorganizing the canonical hydrodynamic expansion of…

Nuclear Theory · Physics 2010-11-01 Mauricio Martinez , Michael Strickland

The asymptotic derivation of a new family of one-dimensional, weakly nonlinear and weakly dispersive equations that model the flow of an ideal fluid in an elastic vessel is presented. Dissipative effects due to the viscous nature of the…

Fluid Dynamics · Physics 2020-02-20 Dimitrios Mitsotakis , Denys Dutykh , Li Qian

The overdamped dynamics of a charged particle driven by an uniform electric field through a random sequence of scatterers in one dimension is investigated. Analytic expressions of the mean velocity and of the velocity power spectrum are…

Chaotic Dynamics · Physics 2009-11-07 H. Kunz , R. Livi , A. Suto

Galactic transport models for cosmic rays involve the diffusive motion of these particles in the interstellar medium. Due to the large-scale structured galactic magnetic field this diffusion is anisotropic with respect to the local field…

High Energy Astrophysical Phenomena · Physics 2013-06-07 Frederic Effenberger , Horst Fichtner , Klaus Scherer , Ingo Büsching

A non-equilibrium thermodynamics model able to analyze the combined effect of diffusion and adsorption in porous materials is proposed. The model considers the coupled dynamics of the diffusive phase, described by a diffusion type equation,…

Materials Science · Physics 2015-06-04 I. Santamaria-Holek , Z. J. Grzywna , J. M. Rubi

We study the steady laminar advective transport of a diffusive passive scalar released at the base of narrow three-dimensional longitudinal open channels with non-absorbing side walls and rectangular or truncated-wedge-shaped…

Fluid Dynamics · Physics 2020-02-14 Merlin A. Etzold , Julien R. Landel , Stuart B. Dalziel

Light diffusion is usually associated with thick, opaque media. Indeed, multiple scattering is necessary for the onset of the diffusive regime and such condition is generally not met in almost transparent media. Nonetheless, at long enough…

We introduce a functional framework which is specially suited to formulate several classes of anisotropic evolution equations of tempered diffusion type. Under an amenable set of hypothesis involving a very natural potential function, these…

Analysis of PDEs · Mathematics 2020-06-16 Juan Calvo , Antonio Marigonda , Giandomenico Orlandi