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In recent years, research and development in nanoscale science and technology have grown significantly, with electrical transport playing a key role. A natural challenge for its description is to shed light on anomalous behaviours observed…

Populations and Evolution · Quantitative Biology 2025-04-10 Sara Bernardi , Paolo Begnamino , Marco Pizzi , Lamberto Rondoni

We integrate neural operators with diffusion models to address the spectral limitations of neural operators in surrogate modeling of turbulent flows. While neural operators offer computational efficiency, they exhibit deficiencies in…

Machine Learning · Computer Science 2025-02-14 Vivek Oommen , Aniruddha Bora , Zhen Zhang , George Em Karniadakis

Diffusive transport processes in magnetized plasmas are highly anisotropic, with fast parallel transport along the magnetic field lines sometimes faster than perpendicular transport by orders of magnitude. This constitutes a major challenge…

Plasma Physics · Physics 2024-12-04 Federico D. Halpern , Min-Gu Yoo , Brendan Lyons , Juan Diego Colmenares

An annealed version of the quenched mean-field model for epidemic spread is introduced and investigated analytically and assisted by numerical calculations. The interaction between individuals follows a prescription that is used to generate…

Populations and Evolution · Quantitative Biology 2025-01-22 K. M. Kim , M. O. Hase

We study quantum percolation which is described by a tight-binding Hamiltonian containing only off-diagonal hopping terms that are generally in quenched binary disorder (zero or one). In such a system, transmission of a quantum particle is…

Disordered Systems and Neural Networks · Physics 2007-09-20 Md Fhokrul Islam , Hisao Nakanishi

Fractional Brownian motion (fBm) is a ubiquitous diffusion process in which the memory effects of the stochastic transport result in the mean squared particle displacement following a power law, $\langle {\Delta r}^2 \rangle \sim…

Applied Physics · Physics 2020-10-06 Raviteja Vangara , Kim Ø. Rasmussen , Dimiter N. Petsev , Golan Bel , Boian S. Alexandrov

A recently proposed theory for diffusion-limited aggregation (DLA), which models this system as a random branched growth process, is reviewed. Like DLA, this process is stochastic, and ensemble averaging is needed in order to define…

Condensed Matter · Physics 2009-10-28 Thomas C. Halsey , Katsuya Honda , Bertrand Duplantier

Recent studies have indicated that the coarse grained dynamics of a large class of traffic models and driven-diffusive systems may be described by urn models. We consider a class of one-dimensional urn models whereby particles hop from an…

Statistical Mechanics · Physics 2009-11-10 E. Levine , D. Mukamel , G. Ziv

Fractional Brownian motion is a Gaussian stochastic process with stationary, long-time correlated increments and is frequently used to model anomalous diffusion processes. We study numerically fractional Brownian motion confined to a finite…

Statistical Mechanics · Physics 2019-03-22 T. Guggenberger , G. Pagnini , T. Vojta , R. Metzler

A conditional diffusion model has been developed to analyze intricate conductance fluctuations called universal conductance fluctuations or quantum fingerprints appearing in quantum transport phenomena. The model reconstructs impurity…

Mesoscale and Nanoscale Physics · Physics 2025-06-11 Naoto Yokoi , Yuki Tanaka , Yukito Nonaka , Shunsuke Daimon , Junji Haruyama , Eiji Saitoh

Diffusion models (DMs) have emerged as a powerful class of generative AI models, showing remarkable potential in anomaly detection (AD) tasks across various domains, such as cybersecurity, fraud detection, healthcare, and manufacturing. The…

Machine Learning · Computer Science 2025-02-28 Jing Liu , Zhenchao Ma , Zepu Wang , Chenxuanyin Zou , Jiayang Ren , Zehua Wang , Liang Song , Bo Hu , Yang Liu , Victor C. M. Leung

An intermittent nonlinear map generating subdiffusion is investigated. Computer simulations show that the generalized diffusion coefficient of this map has a fractal, discontinuous dependence on control parameters. An amended continuous…

In this lecture we present an overview of the physics of irreversible fractal growth process, with particular emphasis on a class of models characterized by {\em quenched disorder}. These models exhibit self-organization, with critical…

Statistical Mechanics · Physics 2007-05-23 L. Pietronero , R. Cafiero , A. Gabrielli

Deviations from Brownian motion leading to anomalous diffusion are found in transport dynamics from quantum physics to life sciences. The characterization of anomalous diffusion from the measurement of an individual trajectory is a…

The distribution of entanglement between the nodes of a quantum network plays a fundamental role in quantum information applications. In this work, we investigate the dynamics of a network of qubits where each edge corresponds to an…

It is shown that the distribution functions of the diffusion coefficient are very similar in the standard model of quantum diffusion in a disordered metal and in a model of classical diffusion in a disordered medium: in both cases the…

Condensed Matter · Physics 2007-05-23 I. V. Lerner

We show that multichannel quantum systems with uncorrelated but asymmetric Anderson-type disorder can exhibit anomalous diffusion, even in the absence of heavy-tailed disorder. Using a minimal two-channel model with channel asymmetry, we…

Mesoscale and Nanoscale Physics · Physics 2025-10-02 Hazan Ozkan , Stephan Roche , Haldun Sevincli

Diffusion models have gained attention for their ability to represent complex distributions and incorporate uncertainty, making them ideal for robust predictions in the presence of noisy or incomplete data. In this study, we develop and…

Machine Learning · Computer Science 2024-11-05 Yilin Zhuang , Sibo Cheng , Karthik Duraisamy

Anomalous diffusion, process in which the mean-squared displacement of system states is a non-linear function of time, is usually identified in real stochastic processes by comparing experimental and theoretical displacements at relatively…

Data Analysis, Statistics and Probability · Physics 2013-05-29 Serge F. Timashev , Yuriy S. Polyakov , Pavel I. Misurkin , Sergey G. Lakeev

We introduce a class of partial differential equations on metric graphs associated with mixed evolution: on some edges we consider diffusion processes, on other ones transport phenomena. This yields a system of equations with possibly…

Analysis of PDEs · Mathematics 2021-03-29 Amru Hussein , Delio Mugnolo