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We consider a time-continuous branching random walk on a one-dimensional lattice on which there is one center (lattice point) of particle generation, called branching source. The generation of particles in the branching source is described…

Probability · Mathematics 2023-12-19 E. Filichkina , E. Yarovaya

A Langevin process diffusing in a periodic potential landscape has a time dependent diffusion constant which means that its average mean squared displacement (MSD) only becomes linear at late times. The long time, or effective diffusion…

Statistical Mechanics · Physics 2015-06-19 David S. Dean , Gleb Oshanin

We consider the inverse source problem of determining a source term depending on both time and space variable for fractional and classical diffusion equations in a cylindrical domain from boundary measurements. With suitable boundary…

Analysis of PDEs · Mathematics 2020-01-08 Yavar Kian , Masahiro Yamamoto

From the exact single step evolution equation of the two-point correlation function of a particle distribution subjected to a stochastic displacement field $\bu(\bx)$, we derive different dynamical regimes when $\bu(\bx)$ is iterated to…

Statistical Mechanics · Physics 2011-11-10 Andrea Gabrielli , Fabio Cecconi

Time plays an essential role in the diffusion of information, influence and disease over networks. In many cases we only observe when a node copies information, makes a decision or becomes infected -- but the connectivity, transmission…

Social and Information Networks · Computer Science 2011-05-05 Manuel Gomez Rodriguez , David Balduzzi , Bernhard Schölkopf

The narrow escape problem deals with the calculation of the mean escape time (MET) of a Brownian particle from a bounded domain through a small hole on the domain's boundary. Here we develop a formalism that allows us to evaluate the…

Statistical Mechanics · Physics 2018-03-28 Tal Agranov , Baruch Meerson

This paper considers the narrow escape problem of a Brownian particle within a three-dimensional Riemannian manifold under the influence of the force field. We compute an asymptotic expansion of mean sojourn time for Brownian particles. As…

Probability · Mathematics 2023-07-19 Medet Nursultanov , William Trad , Leo Tzou

Accurate modeling of ultrasound wave propagation is essential for high-fidelity simulation and imaging in ultrasonic testing. A primary challenge lies in characterizing the excitation source, particularly for transducers with large…

Medical Physics · Physics 2026-03-26 Tim Bürchner , Simon Schmid , Ernst Rank , Stefan Kollmannsberger , Andreas Fichtner

In this review, we present the encounter-based approach to target search problems, in which the diffusive dynamics is described by the joint probability of the position of the particle and the number of its encounters with a given target…

Statistical Mechanics · Physics 2025-07-16 Denis S. Grebenkov

The target of our study is to approximate numerically and, in some particular physically relevant cases, also analytically, the residence time of particles undergoing an asymmetric simple exclusion dynamics on a stripe. The source of…

Cellular Automata and Lattice Gases · Physics 2015-11-18 Emilio N. M. Cirillo , Adrian Muntean , Oleh Krehel , Rutger van Santen , Aditya Sengar

Developing behavioral policies designed to efficiently solve target-search problems is a crucial issue both in nature and in the nanotechnology of the 21st century. Here, we characterize the target-search strategies of simple microswimmers…

Soft Condensed Matter · Physics 2023-07-25 Harpreet Kaur , Thomas Franosch , Michele Caraglio

An elementary approach to characterizing the impact of noise scheduling and time discretization in generative diffusion models is developed. We first utilize the Cram\'er-Rao bound to identify the Gaussian setting as a fundamental…

Information Theory · Computer Science 2026-02-10 Qiang Sun , H. Vincent Poor , Wenyi Zhang

Adsorption to a surface, reversible-binding, and trapping are all prevalent scenarios where particles exhibit "stickiness". Escape and first-passage times are known to be drastically affected, but detailed understanding of this phenomenon…

Statistical Mechanics · Physics 2023-12-06 Yuval Scher , Shlomi Reuveni , Denis S. Grebenkov

We study the late time dynamics of a single active Brownian particle in two dimensions with speed $v_0$ and rotation diffusion constant $D_R$. We show that at late times $t\gg D_R^{-1}$, while the position probability distribution…

Statistical Mechanics · Physics 2019-12-18 Urna Basu , Satya N. Majumdar , Alberto Rosso , Gregory Schehr

Single-file diffusion is a paradigmatic model for the transport of Brownian colloidal particles in narrow one-dimensional channels, such as those found in certain porous media, where the particles cannot cross each other. We consider a…

Statistical Mechanics · Physics 2025-01-07 Benjamin Sorkin , David S. Dean

This paper develops a novel approach to the problem of source current identification for the diffusion equation in connection with geophysical self-potential measurements. The problem is split into two subproblems: (a) the scalar source…

Geophysics · Physics 2019-01-15 Mikhail Malovichko , Nikolay Yavich

Flow matching has recently emerged as a promising alternative to diffusion-based generative models, particularly for text-to-image generation. Despite its flexibility in allowing arbitrary source distributions, most existing approaches rely…

Computer Vision and Pattern Recognition · Computer Science 2026-02-06 Junwan Kim , Jiho Park , Seonghu Jeon , Seungryong Kim

We discovered a class of self-similar solutions in nonlinear models describing the formation of morphogen gradients, the concentration fields of molecules acting as spatial regulators of cell differention in developing tissues. These models…

Quantitative Methods · Quantitative Biology 2015-05-28 Cyrill B. Muratov , Peter V. Gordon , Stanislav Y. Shvartsman

We propose a novel framework for analyzing the dynamics of distribution shift in real-world systems that captures the feedback loop between learning algorithms and the distributions on which they are deployed. Prior work largely models…

Machine Learning · Computer Science 2023-10-31 Lauren Conger , Franca Hoffmann , Eric Mazumdar , Lillian Ratliff

We employ renewal processes to characterize the spatiotemporal dynamics of an active Brownian particle under stochastic orientational resetting. By computing the experimentally accessible intermediate scattering function (ISF) and…

Soft Condensed Matter · Physics 2024-05-14 Yanis Baouche , Thomas Franosch , Matthias Meiners , Christina Kurzthaler