相关论文: Modified initial power spectrum and too big to fai…
We investigate the impact of early-time initial conditions on nonlinear structure formation and evolution within the framework of the semi-analytical Excursion Set Theory (EST). Our analysis reveals that adding a Gaussian bump to the…
We computed the power spectrum of weak cosmic shear in models with non-Gaussian primordial density fluctuations. Cosmological initial conditions deviating from Gaussianity have recently attracted much attention in the literature, especially…
The standard structure formation scenario is successful on linear scales. Several apparent problems affect it however at galactic scales, such as the small scale problems at low redshift and more recent issues involving early massive galaxy…
The primordial matter power spectrum quantifies fluctuations in the distribution of dark matter immediately following inflation. Over cosmic time, over-dense regions of the primordial density field grow and collapse into dark matter halos,…
We investigate a set of cosmological models for which the primordial power spectrum has a large-scale power deficit. The standard power-law spectrum is subject to long-wavelength modifications described by some new parameters, resulting in…
We develop the halo model of large-scale structure as an accurate tool for probing primordial non-Gaussianity. In this study we focus on understanding the matter clustering at several redshifts. The primordial non-Gaussianity is modeled as…
We present models for the dark and luminous mass structure of 12 strong lensing early-type galaxies (ETGs). We combine pixel-based modelling of multiband HST/ACS imaging with Jeans modelling of kinematics obtained from Keck/ESI spectra to…
We study constraints on primordial mode-coupling from the power spectrum, squeezed-limit bispectrum and collapsed trispectrum of matter and halos. We describe these statistics in terms of long-wavelength $2$-point functions involving the…
For a Gaussian spectrum of primordial density fluctuations, ultracompact minihalos (UCMHs) of dark matter are expected to be produced in much greater abundance than, e.g., primordial black holes. Forming shortly after matter-radiation…
We consider the consequences of a matter power spectrum which rises on small scales until eventually being cutoff by microphysical processes associated with the particle nature of dark matter. Evolving the perturbations of a weakly…
We study dark energy cosmological models, extensions of the standard model of particles, characterized by having an extra relativistic energy density at very early times, and that rapidly dilute after a phase transition occurs. These models…
This work investigates a set of cosmological collisionless N-body simulations with featured power spectra of initial perturbations in the context of the core-cusp and satellites problems. On the studied power spectra some scales of…
Recently is has been suggested that the dearth of small halos around the Milky Way arises due to a modification of the primordial power spectrum of fluctuations from inflation. Such modifications would be expected to alter the formation of…
We present cosmological dark matter (DM)--only zoom-in simulations of a Milky Way analog originating from enhanced linear matter power spectra $P(k)$ relative to the standard cold, collisionless DM (CDM) cosmology. We consider a Gaussian…
Although the currently favored cold dark matter plus cosmological constant model for structure formation assumes an n=1 scale-invariant initial power spectrum, most inflation models produce at least mild deviations from n=1. Because the…
We present the first simulations within an effective theory of structure formation (ETHOS), which includes the effect of interactions between dark matter and dark radiation on the linear initial power spectrum and dark matter…
While large scale primordial non-Gaussianity is strongly constrained by present-day data, there are no such constraints at Mpc scales. Here we investigate the effect of significant small-scale primordial non-Gaussianity on structure…
Recent interest in primordial black holes as a possible dark matter candidate has motivated the reanalysis of previous methods for constraining massive astrophysical compact objects in the Milky Way halo and beyond. In order to derive these…
We study the effect of dark matter (DM) being encapsulated in primordial black holes (PBHs) on the power spectrum of density fluctuations $P(k)$; we also look at its effect on the abundance of haloes and their clustering. We allow the…
Non-gaussianity in the initial conditions of the universe is one of the most powerful mechanisms to discriminate among the competing theories of the early universe. Measurements using bispectrum of cosmic microwave background anisotropies…