112 research outputs found
Particles approximations of Vlasov equations with singular forces : Propagation of chaos
We obtain the mean field limit and the propagation of chaos for a system of
particles interacting with a singular interaction force of the type
, with in dimension . We also provide
results for forces with singularity up to but with large enough
cut-off. This last result thus almost includes the most interesting case of
Coulombian or gravitational interaction, but it is also interesting when the
strength of the singularity is larger but close to one, in which case
it allows for very small cut-off.Comment: 47 pages. This version: improvement of the presentation, in
particular of the deterministic result
Cellulose Biodegradation Models; An Example of Cooperative Interactions in Structured Populations
We introduce various models for cellulose bio-degradation by micro-organisms.
Those models rely on complex chemical mechanisms, involve the structure of the
cellulose chains and are allowed to depend on the phenotypical traits of the
population of micro-organisms. We then use the corresponding models in the
context of multiple-trait populations. This leads to classical, logistic type,
reproduction rates limiting the growth of large populations but also, and more
surprisingly, limiting the growth of populations which are too small in a
manner similar to the effects seen in populations requiring cooperative
interactions (or sexual reproduction). This study hence offers a striking
example of how some mechanisms resembling cooperation can occur in structured
biological populations, even in the absence of any actual cooperation.Comment: 37 pages, accepted to ESAIM: Mathematical Modelling and Numerical
Analysis (2017
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