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# Methods and Applications of Analysis

## Volume 16 (2009)

### Number 3

### Concentration in Lotka-Volterra Parabolic or Integral Equations: A General Convergence Result

Pages: 321 – 340

DOI: http://dx.doi.org/10.4310/MAA.2009.v16.n3.a4

#### Authors

#### Abstract

We study two equations of Lotka-Volterra type that describe the Darwinian evolution of a population density. In the first model a Laplace term represents the mutations. In the second one we model the mutations by an integral kernel. In both cases, we use a nonlinear birth-death term that corresponds to the competition between the traits leading to selection.

In the limit of rare or small mutations, we prove that the solution converges to a sum of moving Dirac masses. This limit is described by a constrained Hamilton-Jacobi equation. This was already proved in Dirac concentrations in "Lotka-Volterra parabolic PDEs", *Indiana Univ. Math. J.*, 57:7 (2008), pp. 3275-3301, for the case with a Laplace term. Here we generalize the assumptions on the initial data and prove the same result for the integro-differential equation.

#### Keywords

Adaptive evolution; Lotka-Volterra equation; Hamilton-Jacobi equation; viscosity solutions; Dirac concentrations

#### 2010 Mathematics Subject Classification

35B25, 35K57, 47G20, 49L25, 92D15