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Related papers: The Critical Patch Size Problem in Random Graphs

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A metapopulations network is a multi-patch habitat system, where populations live and interact in the habitat patches, and individuals disperse from one patch to the other via dispersal connections. The loss of dispersal connections among…

Dynamical Systems · Mathematics 2019-09-13 Dinesh Kumar , Soumyendu Raha

We consider the Dirichlet Laplacian in a domain two three-dimensional parallel layers having common boundary and coupled by a window. The window produces the bound states below the essential spectrum; we obtain two-sided estimates for them.…

Mathematical Physics · Physics 2007-05-23 Denis Borisov

In this paper, our main goal is to study the evolution problem associated with the Laplacian operator with Dirichlet boundary conditions on a regular tree. To this end, we place special emphasis on the associated first eigenvalue problem,…

Analysis of PDEs · Mathematics 2026-03-24 Leandro M. Del Pezzo , Nicolas Frevenza , Julio D. Rossi

Identifying the critical domain size necessary for a population to persist is an important question in ecology. Both demographic and environmental stochasticity impact a population's ability to persist. Here we explore ways of including…

Populations and Evolution · Quantitative Biology 2016-01-22 Jody R. Reimer , Michael B. Bonsall , Philip K. Maini

The graph invariant examined in this paper is the largest eigenvalue of the adjacency matrix of a graph. Previous work demonstrates the tight relationship between this invariant, the birth and death rate of a contagion spreading on the…

Social and Information Networks · Computer Science 2022-10-27 V. Cherniavskyi , G. Dennis , S. R. Kingan

We deepen the study of Dirichlet eigenvalues in bounded domains where a thin tube is attached to the boundary. As its section shrinks to a point, the problem is spectrally stable and we quantitatively investigate the rate of convergence of…

Analysis of PDEs · Mathematics 2023-09-01 Laura Abatangelo , Roberto Ognibene

Ecologists have long investigated how demographic and movement parameters determine the spatial distribution and critical habitat size of a population. However, most models oversimplify movement behavior, neglecting how landscape…

Populations and Evolution · Quantitative Biology 2024-03-11 Vivian Dornelas , Pablo de Castro , Justin M. Calabrese , William F. Fagan , Ricardo Martinez-Garcia

We consider populations with time-varying growth rates living in sinks. Each population, when isolated, would become extinct. Dispersal-induced growth (DIG) occurs when the populations are able to persist and grow exponentially when…

Dynamical Systems · Mathematics 2024-02-21 Michel Benaim , Claude Lobry , Tewfik Sari , Edouard Strickler

The strong Allee effect plays an important role on the evolution of population in ecological systems. One important concept is the Allee threshold that determines the persistence or extinction of the population in a long time. In general, a…

Analysis of PDEs · Mathematics 2024-08-05 Fanze Kong , Juncheng Wei

We study the asymptotic Dirichlet problem for $f$-minimal graphs in Cartan-Hadamard manifolds $M$. $f$-minimal hypersurfaces are natural generalizations of self-shrinkers which play a crucial role in the study of mean curvature flow. In the…

Differential Geometry · Mathematics 2019-07-26 Jean-Baptiste Casteras , Esko Heinonen , Ilkka Holopainen

Classical ecological theory predicts that environmental stochasticity increases extinction risk by reducing the average per-capita growth rate of populations. To understand the interactive effects of environmental stochasticity, spatial…

Probability · Mathematics 2015-12-16 Steven N. Evans , Peter L. Ralph , Sebastian J. Schreiber , Arnab Sen

We are interested in the spectrum of the Dirichlet Laplacian in thin broken strips with angle $\alpha$. Playing with symmetries, this leads us to investigate spectral problems for the Laplace operator with mixed boundary conditions in…

Analysis of PDEs · Mathematics 2026-05-26 Lucas Chesnel , Sergei A. Nazarov

We pursue the task of developing a finite population counterpart to Eigen's model. We consider the classical Wright-Fisher model describing the evolution of a population of size $m$ of chromosomes of length $\ell$ over an alphabet of…

Probability · Mathematics 2016-08-14 Raphaël Cerf

When considering a graph problem from a parameterized point of view, the parameter chosen is often the size of an optimal solution of this problem (the "standard" parameter). A natural subject for investigation is what happens when we…

Computational Complexity · Computer Science 2013-10-14 Nicolas Bourgeois , Konrad K. Dabrowski , Marc Demange , Vangelis Th. Paschos

This work deals with the isogeometric Galerkin discretization of the eigenvalue problem related to the Laplace operator subject to homogeneous Dirichlet boundary conditions on bounded intervals. This paper uses GLT theory to study the…

Numerical Analysis · Mathematics 2024-01-05 N. Lamsahel , A. El Akri , A. Ratnani

This article is concerned with a version of the contact process with sexual reproduction on a graph with two levels of interactions modeling metapopulations. The population is spatially distributed into patches and offspring are produced in…

Probability · Mathematics 2013-07-26 Nicolas Lanchier

We study a two-species competition model in a patchy advective environment, where the species are subject to both directional drift and undirectional random dispersal between patches and there are losses of individuals in the downstream end…

Dynamical Systems · Mathematics 2023-03-22 Shanshan Chen , Junping Shi , Zhisheng Shuai , Yixiang Wu

For a given graph $H$, its subdivisions carry the same topological structure. The existence of $H$-subdivisions within a graph $G$ has deep connections with topological, structural and extremal properties of $G$. One prominent example of…

Combinatorics · Mathematics 2023-08-22 Seonghyuk Im , Jaehoon Kim , Younjin Kim , Hong Liu

Bound states of the Hamiltonian describing a quantum particle living on three dimensional straight strip of width $d$ are investigated. We impose the Neumann boundary condition on the two concentric windows of the radii $a$ and $ b$ located…

Mathematical Physics · Physics 2015-05-20 Hatem Najar , Oleg Olendski

Source-sink systems are metapopulations of habitat patches with different, and possibly temporally varying, habitat qualities, which are commonly used in ecology to study the fate of spatially extended natural populations. We propose new…

Probability · Mathematics 2012-10-18 Vincent Bansaye , Amaury Lambert