Related papers: Large-scale tidal fields on primordial density per…
By using direct numerical simulations (DNS) at unprecedented resolution we study turbulence under rotation in the presence of simultaneous direct and inverse cascades. The accumulation of energy at large scale leads to the formation of…
Using a sample of galaxy groups selected from the Sloan Digital Sky Survey Data Release 7 (SDSS DR7), we examine the alignment between the orientation of galaxies and their surrounding large scale structure in the context of the cosmic web.…
One way of recovering information about the initial conditions of the Universe is by measuring features of the cosmological density field which are preserved during gravitational evolution and galaxy formation. In this paper we study the…
Recently, we proposed a self-propelled particle model with competing alignment interactions: nearby particles tend to align their velocities whereas they anti-align their direction of motion with particles which are further away [R.…
Our goal is to see how density waves of different scale combine to form voids between galaxy systems of various scale. We perform numerical simulations of structure formation in cubes of size 100 and 256 Mpc/h, with resolutions 256^3 and…
We argue that a universal density profile for dark matter halos arises as a natural consequence of hierarchical structure formation. It is a fixed point in the process of repeated mergers. We present analytic and numerical arguments for the…
The most distinctive feature of the primordial density inhomogeneities that existed in the cosmic plasma at the instant of decoupling is their scale invariant power spectrum ${\cal P}(k) \sim k$ over the range $k \ll H_{eq}$ of modes with…
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…
The obliquities of planet-hosting stars are clues about the formation of planetary systems. Previous observations led to the hypothesis that for close-in giant planets, spin-orbit alignment is enforced by tidal interactions. Here, we…
An initially homogeneous freely evolving fluid of inelastic hard spheres develops inhomogeneities in the flow field (vortices) and in the density field (clusters), driven by unstable fluctuations. Their spatial correlations, as measured in…
We calculate the density and gravitational wave spectrums generated in a version of string cosmology termed pre-big bang scenario. The large scale structures are originated from quantum fluctuations of the metric and dilaton field during a…
I review the standard paradigm for understanding the formation and evolution of cosmic structure, based on the gravitational instability of dark matter, but many variations on this basic theme are viable. Despite the great progress that has…
We revise the statistical properties of the primordial cosmological density anisotropies that, at the time of matter radiation equality, seeded the gravitational development of large scale structures in the, otherwise, homogeneous and…
In this paper we specifically studied one aspect of foreground primordial matter density perturbations: the relative gravitational time delay between a pair of light paths converging towards an observer and originating from two points on…
Galaxy clusters show large-scale azimuthal X-ray surface brightness fluctuations known as cold fronts. Cold fronts are argued to originate due to sloshing driven by sub-halo passage at close proximity to the cluster center. While this…
High spatial resolution observations of protoplanetary disks (PPDs) by ALMA have revealed many details that are providing interesting constraints on the disk physics as well as dust dynamics, both of which are essential for understanding…
Cosmological perturbations of sufficiently long wavelength admit a fluid dynamic description. We consider modes with wavevectors below a scale $k_m$ for which the dynamics is only mildly non-linear. The leading effect of modes above that…
Long-wavelength matter inhomogeneities contain cleaner information on the nature of primordial perturbations as well as the physics of the early universe. The large-scale coherent overdensity and tidal force, not directly observable for a…
Primordial magnetic field (PMF) is one of the feasible candidates to explain observed large-scale magnetic fields, for example, intergalactic magnetic fields. We present a new mechanism that brings us information about PMFs on small scales…
The observed large-scale alignment of polarization angles and galaxy axis have been challenging the fundamental assumption of homogeneity and isotropy in standard cosmology since more than two decades. The intergalactic magnetic field, and…