  In this review we outline the major points of ab-initio cosmological models
focusing on some galaxy evolution unresolved problems. In particular our
knowledge of the star formation rate which leads galaxy evolution, i.e.
luminosity, colors and dust enrichment, is still very poor. Smoothed particle
hydrodynamic simulations including chemo-photometric evolutionary population
synthesis models of isolated collapsing systems endowed with triaxial dark
matter halos, gas and the star formation switched on, are a useful tool to shed
light on several open questions. This approach, which allows a greater particle
resolution than a fully consistent cosmological scenario, gives us important
insights into connections between dark and luminous matter. Both the initial
properties of the halo, as so as its geometry and dynamical state, and total
mass of the system, drive the galaxy formation and evolution. In our simple
framework spiral galaxies arise only in systems with both a total mass less
than 1.e12 solar masses and a critical value of the baryonic-to-total-mass
ratio, around its cosmological value, 0.1. For the same value of such a ratio
more massive systems host more luminous and redder galaxies, as a consequence
of the stronger burst of star formation arising into their halos earlier on.
Moreover the star formation does not switch on in the less massive DM halos so
that the critical mass to entail a luminous system is 1.e11 solar masses. For a
given total mass, higher values of the baryonic-to-total-mass ratio provide
galaxies with lower rotational support so that no constraints to the total mass
of the system hosting an elliptical galaxy have been derived.
