collaborators

5 papers

math.AP2025

Impact of diffusion mechanisms on persistence and spreading

Nathanaël Boutillon, Yong-Jung Kim, Lionel Roques

We examine a generalized KPP equation with a ``-diffusion", which is a framework that unifies various standard linear diffusion regimes: Fickian diffusion (), Stratonovic…

math.AP2025

The principal eigenvalue problem for a strongly anisotropic second-order elliptic operator

Nathanaël Boutillon

We consider an elliptic operator in which the second-order term is very small in one direction. In this regime, we study the behaviour of the principal eigenfunction and of the pri…

math.AP2025

Periodic KPP equations: new insights into persistence, spreading, and the role of advection

Nathanaël Boutillon, François Hamel, Lionel Roques

We focus on the persistence and spreading properties for a heterogeneous Fisher-KPP equation with advection. After reviewing the different notions of persistence and spreading spee…

math.AP2025

Reaction-diffusion model for a population structured in phenotype and space I -- Criterion for persistence

Nathanaël Boutillon, Luca Rossi

We consider a reaction-diffusion model for a population structured in phenotype. We assume that the population lives in a heterogeneous periodic environment, so that a given phenot…

math.AP2024

Qualitative properties of the spreading speed of a population structured in space and in phenotype

Nathanaël Boutillon

We consider a nonlocal Fisher-KPP equation that models a population structured in space and in phenotype. The population lives in a heterogeneous periodic environment: the diffusio…