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Populations are often subject to catastrophes that cause mass removal of individuals. Many stochastic growth models have been considered to explain such dynamics. Among the results reported, it has been considered whether dispersion…

Probability · Mathematics 2023-08-21 F. Duque , V. V. Junior , F. P. Machado , A. Roldan-Correa

We consider birth-and-death processes of objects (animals) defined in ${\bf Z}^d$ having unit death rates and random birth rates. For animals with uniformly bounded diameter we establish conditions on the rate distribution under which the…

Probability · Mathematics 2007-05-23 Roberto Fernandez , Pablo A. Ferrari , Gustavo R. Guerberoff

In studies of recurrent events, joint modeling approaches are often needed to allow for potential dependent censoring by a terminal event such as death. Joint frailty models for recurrent events and death with an additional dependence…

Methodology · Statistics 2023-04-25 Marie Böhnstedt , Jutta Gampe , Monique A. A. Caljouw , Hein Putter

Multiscale dynamics are ubiquitous in applications of modern science. Because of time scale separation between relatively small set of slowly evolving variables and (typically) much larger set of rapidly changing variables, direct numerical…

Dynamical Systems · Mathematics 2016-04-08 Rafail V. Abramov

We propose a stochastic model for evolution. Births and deaths of species occur with constant probabilities. Each new species is associated with a fitness sampled from the uniform distribution on [0,1]. Every time there is a death event…

Probability · Mathematics 2010-11-09 Herve Guiol , Fabio P. Machado , Rinaldo B. Schinazi

We finely describe the "coming down from infinity" for birth and death processes which eventually become extinct. Our biological motivation is to study the decrease of regulated populations which are initially large. Under general…

Probability · Mathematics 2013-10-29 Vincent Bansaye , Sylvie Méléard , Mathieu Richard

Two scenarios for cluster production have since long been discussed in the literature: i) direct emission of the clusters from a (grand canonical) thermal source or ii) subsequent formation of the clusters by coalescence of single nucleons.…

Nuclear Theory · Physics 2016-05-18 Zuzana Feckova , Jan Steinheimer , Boris Tomasik , Marcus Bleicher

The dynamics of heavy particles suspended in turbulent flows is of fundamental importance for a wide range of questions in astrophysics, atmospheric physics, oceanography, and technology. Laboratory experiments and numerical simulations…

Fluid Dynamics · Physics 2016-09-21 K. Gustavsson , B. Mehlig

We consider a discrete model that describes a locally regulated spatial population with mortality selection. This model was studied in parallel by Bolker and Pacala and Dieckmann, Law and Murrell. We first generalize this model by adding…

Probability · Mathematics 2007-05-23 Nicolas Fournier , Sylvie Meleard

In this work we study the consequences of a longitudinal Bjorken expansion and a Hubble-like temperature cooling scenario on a 1+1D non-linear model of the diffusive dynamics of fluctuations in the net-baryon density. The equilibrium…

Nuclear Theory · Physics 2023-02-01 Grégoire Pihan , Marcus Bluhm , Masakiyo Kitazawa , Taklit Sami , Marlene Nahrgang

The classical Luria-Delbr\"uck model for fluctuation analysis is extended to the case where cells can either divide or die at the end of their generation time. This leads to a family of probability distributions generalizing the…

Populations and Evolution · Quantitative Biology 2013-05-30 Bernard Ycart

There is a deep connection between the ground states of transverse-field spin systems and the late-time distributions of evolving viral populations -- within simple models, both are obtained from the principal eigenvector of the same…

Statistical Mechanics · Physics 2021-01-13 C. L. Baldwin , S. Shivam , S. L. Sondhi , M. Kardar

The presence of one or more species at some spatial locations but not others is a central matter in ecology. This phenomenon is related to ecological pattern formation. Nonlocal interactions can be considered as one of the mechanisms…

Populations and Evolution · Quantitative Biology 2017-12-29 Ozgur Aydogmus

Populations exhibiting partial migration consist of two groups of individuals: Those that mi- grate between habitats, and those that remain fixed in a single habitat. We propose several discrete-time population models to investigate the…

Dynamical Systems · Mathematics 2016-10-31 Anushaya Mohapatra , Haley A. Ohms , David A. Lytle , Patrick De Leenheer

We consider population models in which the individuals reproduce, die and also migrate in space. The population size scales according to some parameter $N$, which can have different interpretations depending on the context. Each individual…

Probability · Mathematics 2012-12-21 Ankit Gupta

A considerable number of systems have recently been reported in which Brownian yet non-Gaussian dynamics was observed. These are processes characterised by a linear growth in time of the mean squared displacement, yet the probability…

Statistical Mechanics · Physics 2018-11-26 V. Sposini , A. V. Chechkin , F. Seno , G. Pagnini , R. Metzler

In many-particle diffusions, particles that move the furthest and fastest can play an outsized role in physical phenomena. A theoretical understanding of the behavior of such extreme particles is nascent. A classical model, in the spirit of…

Statistical Mechanics · Physics 2024-11-22 Jacob B. Hass , Aileen N. Carroll-Godfrey , Eric I. Corwin , Ivan Z. Corwin

Advection of entities induced by gradients in attractant concentration fields is observed via diffusiophoresis in colloids and via chemotaxis in microorganisms. Mathematically, both diffusiophoresis and chemotaxis follow similar…

Populations and Evolution · Quantitative Biology 2024-10-07 Benjamin M. Alessio , Ankur Gupta

We analyse how the sampling dynamics of distributions evolve in score-based diffusion models using cross-fluctuations, a centered-moment statistic from statistical physics. Specifically, we show that starting from an unbiased isotropic…

Machine Learning · Computer Science 2026-05-04 Sai Niranjan Ramachandran , Manish Krishan Lal , Suvrit Sra

Evidences are presented concerning tantalizing regularities in cities' population-flows in what regards to space and time correlations. The former exhibit a distance-behavior (for large distances) compatible with the inverse square law,…

Applications · Statistics 2012-07-30 A. Hernando , A. Plastino