MG11 
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Anisotropic Hubble expansion of large scale structures

We investigate by mean of Euler-Poisson equations system the dynamics of a distribution of gravitational sources moving under an anisotropic generalization of Hubble expansion. As a result, it turns out that such a behavior requires the distribution to be homogenous. With the aim of understanding the cosmic velocity fields at large scale within the Local Super Cluster, the solutions are interpreted as approximations providing us with an hint on the behavior of the cosmic flow just after decoupling era up to present date, it enables us to put enlightening on the possibility that the observed bulk flow has a kinematic origin, instead of being due exclusively to tidal forces. Among several solutions, we point out a planar kinematics with constant (eternal) and rotational distortion, the velocity field is not potential.

$\Lambda$ effect in the expansion of voids in the universe

We show that the cosmological constant favours significantly the growth of voids in the universe. This dynamical effect is investigated within a newtonian approach with an extension to Friedmann-Lema\^{\i}tre model.