Related papers: Stress effects in structure formation
Many interesting shapes appearing in the biological world are formed by the onset of mechanical instability. In this work we consider how the build-up of residual stress can cause a solid to buckle. In all past studies a fictitious…
Galaxies are gigantic physical systems having a typical size of many tens of thousands of light years. Thus any change at the center of the galaxy will affect the rim only tens of millennia later. Those retardation effects seems to be…
We propose a new model to describe diffusion processes within active deformable media. Our general theoretical framework is based on physical and mathematical considerations, and it suggests to use diffusion tensors directly coupled to…
We investigate the impact of thermal velocities in N-body simulations of structure formation in warm dark matter models. Adopting the commonly used approach of adding thermal velocities, randomly selected from a Fermi-Dirac distribution, to…
We investigate the non-linear evolution of spherical density and velocity perturbations of dark matter and dark energy in the expanding Universe. For that we have used the conservation and Einstein equations to describe the evolution of…
The damping on the fluctuation spectrum and the presence of thermal velocities as properties of warm dark matter particles like sterile neutrinos imprint a distinct signature found from the structure formation mechanisms to the internal…
We present the leading order non-linear density and velocity power spectra in the complete form; previous studies have omitted the vector- and tensor-type perturbations simultaneously excited by the scalar-type perturbation in nonlinear…
The spatial distribution of matter in clusters of galaxies is mainly determined by the dominant dark matter component, however, physical processes involving baryonic matter are able to modify it significantly. We analyse a set of 500 pc…
We study the effect of disorder on the particle density evolution in a classical Hamiltonian driven lattice setup. If the disorder is localized within a finite sub-domain of the lattice, the emergence of strong tails in the density…
We revisit the process of gravitational sedimentation of helium and heavy elements in the intra-cluster medium. We find that helium applies an inward drag force on heavy elements, boosting their sedimentation speed to nearly half its own.…
In this paper, we study the role of shear fields on the evolution of density perturbations embedded in a Friedmann flat background universe, by studying the evolution of a homogeneous ellipsoid model. In this context, we show that while the…
We have resimulated the six galaxy-sized haloes of the Aquarius Project including metal-dependent cooling, star formation and supernova feedback. This allows us to study not only how dark matter haloes respond to galaxy formation, but also…
We carry out fully 3-dimensional simulations of evolution from self-similar, spherically symmetric linear perturbations of a Cold Dark Matter dominated Einstein-de Sitter universe. As a result of the radial orbit instability, the haloes…
The effects of particle discreteness in N-body simulations of Lambda Cold Dark Matter (LambdaCDM) are still an intensively debated issue. In this paper we explore such effects, taking into account the scatter caused by the randomness of the…
We perform numerical evolutions of cosmological scenarios using a standard general relativistic code in spherical symmetry. We concentrate on two different situations: initial matter distributions that are homogeneous and isotropic, and…
We use the non-linear spherical model in cold dark matter (CDM) cosmologies with dark energy to investigate the effects of dark energy on the growth of structure and the formation of virialised structures. We consider dark energy models…
Dark energy is the candidate that can produce effective negative pressure and make the galaxies and galaxy clusters move away from each other in an accelerated way. The structures of the Universe have evolved from some initial primordial…
We consider the evolution of relativistic perturbations in the Einstein-de Sitter cosmological model, including second-order effects. The perturbations are considered in two different settings: the widely used synchronous gauge and the…
We present a simple model that accurately describes various statistical properties of peculiar velocities of dark matter halos. We pay particular attention to the following two effects; first, the evolution of the halo peculiar velocity…
It has recently been shown that relaxed spherically symmetric dark matter halos develop from the inside out, by permanently adapting their inner structure to the boundary conditions imposed by the current accretion rate. Such a growth…