Related papers: The energy shear of protohaloes
Dark matter haloes form from the collapse of matter around special positions in the initial field, those where the local matter flows converge to a point. For such a triaxial collapse to take place, the energy shear tensor -- the source of…
Protohalos, primordial regions in the initial cosmic density field that evolve into dark matter halos, are crucial for understanding cosmic structure formation. Motivated by the potential to reconstruct protohalo positions and shapes from…
The simplest models of dark matter halo formation are based on the heuristic assumption, motivated by spherical collapse, that virialized haloes originate from initial regions that are maxima of the smoothed density field. Here, we replace…
In analytical models of structure formation, protohalos are routinely assumed to be peaks of the smoothed initial density field, with the smoothing filter being spherically symmetric. This works reasonably well for identifying a protohalo's…
We describe an algorithm for identifying ellipsoidal haloes in numerical simulations, and quantify how the resulting estimates of halo mass and shape differ with respect to spherical halo finders. Haloes become more prolate when fit with…
In this paper, we analyze the dynamical evolution of quintessence dark energy induced by the collapse of dark matter halos. Different from other previous studies, we develop a numerical strategy which allows us to calculate the dark energy…
The simplest stochastic halo formation models assume that the traceless part of the shear field acts to increase the initial overdensity (or decrease the underdensity) that a protohalo (or protovoid) must have if it is to form by the…
Dark matter halos grow by hierarchical clustering as they merge together to produce ever larger structures. During these merger processes, the smaller halo can potentially survive as a subhalo of the larger halo, so a galaxy-scale halo…
We investigate the cross-talk between the two key components of tidal-torque theory, the inertia (I) and shear (T) tensors, using a cosmological N-body simulation with thousands of well-resolved haloes. We find that the principal axes of I…
We investigate the influence of the initial proto-galaxies over-densities and masses on their evolution, to understand whether the internal properties of the proto-galactic haloes are sufficient to account for the varied properties of the…
We investigate the build-up of the halo profile out to large scale in a cosmological simulation, focusing on the roles played by the recently proposed depletion radii. We explicitly show that halo growth is accompanied by the depletion of…
(Context) In a Universe dominated by dark matter, halos are continuously accreting mass (violently or not) and such mechanism affects their dynamical state. (Aims) The evolution of dark matter halos in phase-space, and using the phase-space…
Strong gravitational lenses enable direct inference of halo abundance and internal structure, which in turn enable constraints on the nature of dark matter and the primordial matter power spectrum. However, the density profiles of dark…
We simulate the dynamical and chemical evolution of a dwarf galaxy embedded in a dark matter halo, using a three-dimensional N-body/SPH simulation code combined with stellar population synthesis. The initial condition is adopted in accord…
A dark matter halo is commonly defined as a spherical overdensity of matter with respect to a reference density, such as the critical density or the mean matter density of the Universe. Such definitions can lead to a spurious…
It is common practice to describe formal size and mass scales of dark matter halos as spherical overdensities with respect to an evolving density threshold. Here, we critically investigate the evolutionary effects of several such commonly…
Scalar field with generalized kinetic interactions metamorphoses depending on its field value, ranging from cosmological constant to stiff matter. We show that such a scalar field can give rise to temporal enhancement of the curvature…
In two previous papers (Salvador-Sol\'e 2012a,b), it was shown that: i) the typical structural and kinematic properties of haloes in (bottom-up) hierarchical cosmologies endowed with random Gaussian density perturbations of dissipationless…
The evolution in shape of an isolated density enhancement in the early universe is studied through numerical simulations. The formation scenarios of a cold dissipationless collapse and that of a slow accumulation of gas in a dark matter…
The dissipative infall of gas during the formation of a galaxy modifies the density profile and shape of the dark halo. Gas dissipates energy radiatively and sinks to the center of the dark halo forming the luminous part of a galaxy. The…