Research activities
Short presentation:
I work on mathematical models from evolutionary biology and ecology.
I am interested in the description of joint demographic and evolutionary dynamics of populations structured by quantitative traits in heterogeneous environments. Such phenomena can be modeled by nonlocal parabolic Lotka-Volterra type equations or by nonstandard kinetic equations depending on whether or not mixing of the gene pool is taken into account. My previous works mainly concern models with asexual reproduction and with no mixing of the gene pool (hence parabolic Lotka-Volterra type equations). However, more recently I have also become interested in the study of the mixing of the gene pool (due for instance to the exchange of genetic information between bacteria or to sexual reproduction).
Such models have typically various temporal regimes. Some characteristics of such multi-scale equations are that they lead to some concentration phenomena (occurrence of dominant traits) or propagation phenomena (spatial invasions). An important part of my work has been devoted to the development of an asymptotic approach based on Hamilton-Jacobi equations with constraint to study such models. Furthermore, I have been interested in the study of the impact of temporal and spatial heterogeneity on species' range and phenotypic distribution. Another axis of my research is the study of models with heavy-tailed non-local diffusion terms (due for instance to a non-local dispersion or a heavy-tailed mutation distribution).
Articles:
Hamilton-Jacobi approach (homogeneous environments):
- G. Barles, S. Mirrahimi and B. Perthame, Concentration in Lotka-Volterra parabolic or integral equations: a general convergence result. Methods and Applications of Analysis (MAA) Vol. 16.3, (2009) pp. 321-340 (pdf)
- A. Lorz, S. Mirrahimi and B. Perthame, Dirac mass dynamics in a multidimensional nonlocal parabolic
equation, Communications in Partial Differential Equations, Vol. 36, Issue 6, (2011) pp. 1071-1098 (pdf)
- S. Mirrahimi, G. Barles, B. Perthame and P. E. Souganidis, Singular Hamilton-Jacobi equation for the tail problem, SIAM J. Math. Anal. Vol. 44.6, (2012) pp. 4297-4319 (pdf)
- S. Mirrahimi and J.-M. Roquejoffre, Uniqueness in a class of Hamilton-Jacobi equations with constraints, Comptes Rendus Mathematique, Vol. 353, (2015), pp. 489-494: (Online version) (pdf)
- S. Mirrahimi and J.-M. Roquejoffre, A class of Hamilton-Jacobi equations with constraint: uniqueness and constructive approach, Journal of differential equations, Vol. 250.5 (2016), pp. 4717-4738. (pdf)
Models with heavy-tailed diffusion:
- S. Méléard and S. Mirrahimi, Singular limits for reaction-diffusion equations with fractional Laplacian and local or nonlocal nonlinearity, Communications in Partial Differential Equations, Vol. 40.5, (2015), pp. 957-993: (Online version) (pdf)
- S. Mirrahimi, Singular limits for models of selection and mutations with heavy-tailed mutation distribution, J. Math. Pures Appl., Vol. 134 (2020) pp. 179-203 (pdf)
- A. Léculier, J.-M. Roquejoffre, S. Mirrahimi, Propagation in a fractional reaction-diffusion equation in a
periodically hostile environment, J Dyn Diff Equat (2020), https://doi.org/10.1007/s10884-020-09837-4. (pdf)
Temporally heterogeneous environments:
- S. Mirrahimi, B. Perthame and P. E. Souganidis, Time fluctuations in a population model of adaptative dynamics, Annales de l'Institut Henri Poincare (C) Analyse Non Linéaire, Vol. 32.1, (2015) pp. 41-58. (pdf)
- S. Figueroa Iglesias and S. Mirrahimi, Long time evolutionary dynamics of phenotypically structured populations in time-periodic environments, SIAM J. Math. Anal., Vol. 50.5 (2018) pp. 5537-5568. (pdf)
- M. Costa, C. Etchegaray and S. Mirrahimi, Survival criterion for a population subject to selection and mutations; Application to temporally piecewise constant environments, preprint. (pdf)
- S. Figueroa Iglesias and S. Mirrahimi, Selection and mutation in a shifting and fluctuating environment, preprint. (pdf)
Spatially heterogeneous environments:
- S. Mirrahimi and G. Raoul, Population structured by a space variable and a phenotypical trait, Theoretical Population Biology, Vol. 84 (2013) pp. 87-103 (pdf)
- S. Mirrahimi, Adaptation and migration of a population between patches, Discrete and Continuous Dynamical System - B (DCDS-B), Vol. 18.3, (2013) 753-768. (pdf)
- E. Bouin and S. Mirrahimi, A Hamilton-Jacobi limit for a model of population stuctured by space and trait, Comm. Math. Sci., Vol. 13.6 (2015)
pp. 1431-1452. (pdf)
- H. Leman, S. Méléard and S. Mirrahimi, Influence of a spatial structure on the long time behavior of a competitive Lotka-Volterra type system, Discrete and Continuous Dynamical System - B (DCDS-B), Vol. 20.2 (2015) pp. 469-493. (pdf)
- S. Mirrahimi and B. Perthame, Asymptotic analysis of a selection model with space,
J. Math. Pures Appl., Vol. 104 (2015), pp. 1108-1118. (Online version) (pdf)
- S. Gandon and S. Mirrahimi, A Hamilton-Jacobi method to describe the evolutionary equilibria in heterogeneous environments and with non-vanishing effects of mutations, Comptes Rendus - Mathematique, Vol. 355.2, (2016), pp. 155-160, (Online version) (pdf)
- S. Mirrahimi, A Hamilton-Jacobi approach to characterize the evolutionary equilibria in heterogeneous environments, Mathematical Models and Methods in Applied Sciences, Vol. 27.13 (2017) pp. 2425-2460. (pdf)
- S. Mirrahimi and S. Gandon, Evolution of specialization in heterogeneous environments:
equilibrium between selection, mutation and migration, Genetics, Vol. 214.2 (2020) pp. 479-491, https://doi.org/10.1534/genetics.119.302868.
(Main text)(Supplementary information)
Evolution of dispersal:
- E. Bouin, V. Calvez, N. Meunier, S. Mirrahimi, B. Perthame, G. Raoul, and R. Voituriez, Invasion fronts with variable motility: phenotype selection, spatial sorting and wave acceleration, Comptes rendus - Mathématique Vol. 350 (2012) pp. 761-766 (pdf)
- V. Calvez, C. Henderson, S. Mirrahimi, O. Turanova and T. Dumont, Non-local competition slows down front acceleration during dispersal evolution, preprint. (pdf)
Interaction with resources:
- S. Mirrahimi, B. Perthame and J. Y. Wakano, Evolution of species trait through resource competition, J. Math. biol., Vol. 64(7) (2012) pp. 1189
-1223 (pdf)
- S. Mirrahimi, B. Perthame and J. Y. Wakano, Direct competition results from strong competition for limited resource , J. Math. biol., Vol. 68(4) (2014) pp. 931-949.
Other contributions:
- S. Mirrahimi and P. E. Souganidis, A homogenization approach for the motion of motor proteins, Nonlin. Diff. Eq. Appl. (NoDEA), Vol. 20(1) (2013) pp. 129--147 (pdf)
- P. Degond, M. Herda and S. Mirrahimi, A Fokker-Planck approach to the study of robustness in gene expression, preprint. (pdf)
Dissertations and book chapter