Diffuosion

Diffuosion is a theoretical transport phenomenon defined as a diffusion-like spreading process in which the flux and rate of change of a quantity are shaped by nonlinear, time-dependent feedbacks. This can yield oscillatory, pulsatile, or wave-like concentration patterns in space and time.

Unlike classical diffusion, described by Fick's laws with a constant diffusion coefficient, diffuosion incorporates state- and time-dependent diffusion or reaction terms that can generate alternative dynamics, such as periodic fronts or traveling waves.

Mathematical formulation commonly uses a reaction-diffusion framework with a diffusion coefficient D that depends on concentration and time: ∂C/∂t = ∇·(D(C,t)∇C) + R(C,t). Nonlinear feedback, external forcing, or autocatalytic reactions produce complex spatiotemporal behavior.

Contexts include theoretical studies of porous media, catalytic surfaces with oscillatory kinetics, ecological or epidemiological models with mobility, and models of neural tissue or synthetic biology circuits where diffusion interacts with feedback control.

Status: diffuosion is a neologism used in theoretical discussions and is not a universally standardized term. It overlaps with reaction-diffusion theory and diffusion with time-dependent coefficients. Researchers may describe similar phenomena using established frameworks, depending on the specific system under study.