Probing the dark matter density evolution law with large scale structures.

We propose a new method to explore a possible departure from the standard time evolution law for the dark matter density. We looked for a violation of this law by using a deformed evolution law, given by $\rho_c(z) \propto (1+z)^{3+\epsilon}$ and constraining $\epsilon$. The dataset we used for this purpose consists of Strong Gravitational Lensing data obtained from SLOAN Lens ACS, BOSS Emission-line Lens Survey, Strong Legacy Survey SL2S+SLACS; along with galaxy cluster X-ray gas mass fraction data obtained using the Chandra Telescope. Although our analyses show that $\epsilon$ is consistent with zero within 2 $\sigma$ c.l., the current dataset cannot rule out interacting models of dark matter and dark energy.