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The age of the Universe in the $Lambda$CDM cosmology with $Omega_{matter}=0.26$ and $Omega_{Lambda}=0.74$ is the same as in the Milne cosmology which correspods to an almost empty universe. In both cases it is a reciprocal Hubble constant, $1/H_0$, that for now preferred value $H_0=71 km/s/Mpc$ is 13.7 billion years. The most curious coincidence is that at the present time, in the $Lambda$CDM model the decelerated expansion is exactly compensated by the accelerated expansion, as if the Universe coast for 13.7 billion years.
We present a method that extends the capabilities of the PINpointing Orbit-Crossing Collapsed HIerarchical Objects (PINOCCHIO) code, allowing it to generate accurate dark matter halo mock catalogues in cosmological models where the linear growth fact
Associations of dwarf galaxies are loose systems composed exclusively of dwarf galaxies. These systems were identified in the Local Volume for the first time more than thirty years ago. We study these systems in the cosmological framework of the $Lam
We determine the relationship between the turnaround radius, $R_{rm t}$, and mass, $M_{rm t}$, in $Lambda$CDM, and in dark energy scenarios, using an extended spherical collapse model taking into account the effects of shear and vorticity. We find a
We study the formation of galaxies in a Lambda-CDM Universe using high resolution hydrodynamical simulations with a multiphase treatment of gas, cooling and feedback, focusing on the formation of discs. Our simulations follow eight haloes similar in
Understanding the formation and evolution of early-type, spheroid-dominated galaxies is an open question within the context of the hierarchical clustering scenario, particularly, in low-density environments. Our goal is to study the main structural,