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We present a concise derivation for several influential score-based diffusion models that relies on only a few textbook results. Diffusion models have recently emerged as powerful tools for generating realistic, synthetic signals --…

计算机视觉与模式识别 · 计算机科学 2025-10-06 Chicago Y. Park , Michael T. McCann , Cristina Garcia-Cardona , Brendt Wohlberg , Ulugbek S. Kamilov

We consider single-file diffusion in an open system with two species $A,B$ of particles. At the boundaries we assume different reservoir densities which drive the system into a non-equilibrium steady state. As a model we use an…

统计力学 · 物理学 2007-05-23 A. Brzank , G. M. Schütz

A number of discrete time, finite population size models in genetics describing the dynamics of allele frequencies are known to converge (subject to suitable scaling) to a diffusion process in the infinite population limit, termed the…

概率论 · 数学 2021-09-14 Jaromir Sant , Paul A. Jenkins , Jere Koskela , Dario Spano

We study a class of free boundary problems of ecological models with nonlocal and local diffusions, which are natural extensions of free boundary problems of reaction diffusion systems in there local diffusions are used to describe the…

偏微分方程分析 · 数学 2019-09-17 Jianping Wang , Mingxin Wang

For a wide class of continuous-time Markov processes, including all irreducible hypoelliptic diffusions evolving on an open, connected subset of $\RL^d$, the following are shown to be equivalent: (i) The process satisfies (a slightly weaker…

概率论 · 数学 2016-04-27 Ioannis Kontoyiannis , Sean P. Meyn

This paper is concerned with a Lotka-Volterra type competition model with free boundaries in time-periodic environment. One species is assumed to adopt nonlocal dispersal and the other one adopts mixed dispersal, which is a combination of…

偏微分方程分析 · 数学 2021-01-21 Qiaoling Chen , Fengquan Li , Sanyi Tang , Feng Wang

We investigate the competition between barrier slowing down and proliferation induced superdiffusion in a model of population dynamics in a random force field. Numerical results in $d=1$ suggest that a new intermediate diffusion behaviour…

凝聚态物理 · 物理学 2007-05-23 Irene Giardina , Jean-Philippe Bouchaud , Marc Mezard

Defeat and success of the competitive invasion of a populated area is described with a standard Lotka-Volterra competition model. The resident is adapted to the heterogeneous living conditions, i.e., its motion is modelled as…

种群与进化 · 定量生物学 2017-10-12 Michael Bengfort , Ivo Siekmann , Horst Malchow

Diffusion theory is a central tool of modern population genetics, yielding simple expressions for fixation probabilities and other quantities that are not easily derived from the underlying Wright-Fisher model. Unfortunately, the textbook…

种群与进化 · 定量生物学 2022-12-19 Camila Bräutigam , Matteo Smerlak

Diffusion models have made rapid progress in generating high-quality samples across various domains. However, a theoretical understanding of the Lipschitz continuity and second momentum properties of the diffusion process is still lacking.…

机器学习 · 计算机科学 2024-10-15 Yingyu Liang , Zhenmei Shi , Zhao Song , Yufa Zhou

The finite symmetric group S_n provides a natural domain for permutations, yet learning probability distributions on S_n is challenging due to its factorially growing size and discrete, non-Euclidean structure. Recent permutation diffusion…

机器学习 · 计算机科学 2026-03-19 Sizhuang He , Yangtian Zhang , Shiyang Zhang , David van Dijk

Discrete diffusion models (DDMs) are a powerful class of generative models for categorical data, but they typically require many function evaluations for a single sample, making inference expensive. Existing acceleration methods either rely…

机器学习 · 计算机科学 2025-12-16 Yansong Gao , Yu Sun

Recent progresses in single particle tracking have shown evidences of non-Gaussian distribution of displacements in living cells, both near the cellular membrane and inside the cytoskeleton. A similar behavior has also been observed in…

生物物理 · 物理学 2019-05-30 Yann Lanoiselée , Denis S. Grebenkov

We present a concise, self-contained derivation of diffusion-based generative models. Starting from basic properties of Gaussian distributions (densities, quadratic expectations, re-parameterisation, products, and KL divergences), we…

机器学习 · 计算机科学 2025-11-18 Sepehr Maleki , Negar Pourmoazemi

Diffusion models offer stable training and state-of-the-art performance for deep generative modeling tasks. Here, we consider their use in the context of multivariate subsurface modeling and probabilistic inversion. We first demonstrate…

计算机视觉与模式识别 · 计算机科学 2026-01-28 Roberto Miele , Niklas Linde

This paper deals with a nonhomogeneous scalar parabolic equation with possibly degenerate diffusion term; the process has only one stationary state. The equation can be interpreted as modeling collective movements (crowd dynamics, for…

偏微分方程分析 · 数学 2017-02-17 Andrea Corli , Luisa Malaguti

In this paper, we study the diffusion approximation for slow-fast stochastic differential equations with state-dependent switching, where the slow component $X^{\varepsilon}$ is the solution of a stochastic differential equation with…

概率论 · 数学 2025-03-12 Xiaobin Sun , Jue Wang , Yingchao Xie

There have been increasing reports that the diffusion coefficient of macromolecules depends on time and fluctuates randomly. Here, a novel method to elucidate the fluctuating diffusivity from trajectory data is developed. The time-averaged…

统计力学 · 物理学 2017-10-25 Tomoshige Miyaguchi

We study a class of free boundary systems with nonlocal diffusion, which are natural extensions of the corresponding free boundary problems of reaction diffusion systems. As before the free boundary represents the spreading front of the…

偏微分方程分析 · 数学 2019-07-11 Yihong Du , Mingxin Wang , Meng Zhao

The global-in-time existence of bounded weak solutions to the Maxwell-Stefan-Fourier equations in Fick-Onsager form is proved. The model consists of the mass balance equations for the partial mass densities and and the energy balance…

偏微分方程分析 · 数学 2020-11-02 Christoph Helmer , Ansgar Jüngel