Gravitational dynamics
Numerical simulation (IAP)
In usual cosmological scenarios the large-scale structures which we observe
in the present universe (galaxies, clusters,..) have formed by gravitational
instability from small initial density fluctuations. The dynamics of this
system is well understood in the linear regime (where the amplitude of the
perturbations is small) because one can use perturbative methods. However the
non-linear regime remains an open problem. Although this topic is often
tackled with numerical simulations most of my work has focused on analytical
approaches to this problem (theoretical study of the equations of motion or
development of phenomenological models).
Articles:
-
2004, submitted to MNRAS
A simple model for the probability distribution of the density field, from
the quasi-linear to the highly non-linear regime, which is consistent with all
known exact results.
-
2004, A&A, 421, 23
A theoretical study of the Vlasov-Poisson equations which govern the
gravitational dynamics in an expanding universe: large N expansions.
-
2002, A&A, 385, 761
,
2002, A&A, 382, 450
,
2002, A&A, 382, 431
,
2002, A&A, 382, 412
,
2002, A&A, 379, 8
These articles mainly investigate the application of a steepest-descent method
to the formation of large-scale structures from the equations of motion.
-
2000, MNRAS, 311, 234
,
1997, A&A, 328, 435
A comparison of a "stable-clustering" model with numerical simulations, for
the density distribution and multiplicity functions. A detailed theoretical
study of this model.
-
1999, A&A, 347, 757
Description of the non-linear density field in terms of fractals.
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1998, A&A, 337, 655
A model for the density distribution based on a spherical dynamics
approximation.
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