English
Related papers

Related papers: Modified initial power spectrum and too big to fai…

200 papers

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…

Cosmology and Nongalactic Astrophysics · Physics 2025-09-17 Hamed Kameli , Shant Baghram

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…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-14 C. Fedeli , L. Moscardini

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…

Cosmology and Nongalactic Astrophysics · Physics 2020-09-09 Karim H. Seleim , Amr A. El-Zant , A. M. Abdel-Moneim

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,…

Cosmology and Nongalactic Astrophysics · Physics 2022-03-30 Daniel Gilman , Andrew Benson , Jo Bovy , Simon Birrer , Tommaso Treu , Anna Nierenberg

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…

Cosmology and Nongalactic Astrophysics · Physics 2019-08-13 Sandro D. P. Vitenti , Patrick Peter , Antony Valentini

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…

Cosmology and Nongalactic Astrophysics · Physics 2011-08-09 Robert E. Smith , Vincent Desjacques , Laura Marian

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…

Astrophysics of Galaxies · Physics 2018-02-06 Lindsay Oldham , Matthew Auger

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…

Cosmology and Nongalactic Astrophysics · Physics 2018-02-20 Roland de Putter

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…

Cosmology and Nongalactic Astrophysics · Physics 2013-02-19 Torsten Bringmann , Pat Scott , Yashar Akrami

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…

Cosmology and Nongalactic Astrophysics · Physics 2023-06-21 Derek Inman , Kazunori Kohri

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…

Cosmology and Nongalactic Astrophysics · Physics 2024-01-15 Dante V. Gomez-Navarro , Alejandro Aviles , Axel de la Macorra

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…

Cosmology and Nongalactic Astrophysics · Physics 2013-06-14 Vadim Semenov , Sergey Pilipenko , Andrei Doroshkevich , Vladimir Lukash , Elena Mikheeva

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…

Astrophysics · Physics 2009-08-18 Martin White , Rupert A. C. Croft

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…

Cosmology and Nongalactic Astrophysics · Physics 2025-10-23 Ethan O. Nadler , Vera Gluscevic , Andrew Benson

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…

Astrophysics · Physics 2009-11-07 James S. Bullock , Andrew R. Zentner

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…

Cosmology and Nongalactic Astrophysics · Physics 2016-06-14 Mark Vogelsberger , Jesus Zavala , Francis-Yan Cyr-Racine , Christoph Pfrommer , Torsten Bringmann , Kris Sigurdson

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…

Cosmology and Nongalactic Astrophysics · Physics 2023-01-25 Clément Stahl , Thomas Montandon , Benoit Famaey , Oliver Hahn , Rodrigo Ibata

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…

Cosmology and Nongalactic Astrophysics · Physics 2018-06-27 Josh Calcino , Juan Garcia-Bellido , Tamara M. Davis

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…

Cosmology and Nongalactic Astrophysics · Physics 2021-04-28 Nelson Padilla , Juan Magana , Joaquin Sureda , Ignacio Araya

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…

Astrophysics · Physics 2009-02-23 Uros Seljak
‹ Prev 1 2 3 10 Next ›