scholarly journals Cosmic voids in coupled dark energy cosmologies: the impact of halo bias

2015 ◽  
Vol 455 (3) ◽  
pp. 3075-3085 ◽  
Author(s):  
Giorgia Pollina ◽  
Marco Baldi ◽  
Federico Marulli ◽  
Lauro Moscardini
Keyword(s):  
Dark Energy ◽  
Cosmic Voids ◽  
The Impact

scholarly journals Dark Energy Survey year 1 results: the relationship between mass and light around cosmic voids

2019 ◽  
Vol 490 (3) ◽  
pp. 3573-3587 ◽  
Author(s):  
Y Fang ◽  
N Hamaus ◽  
B Jain ◽  
S Pandey ◽  
G Pollina ◽  
...  
Keyword(s):  
Dark Energy ◽  
Signal To Noise Ratio ◽  
Mass Density ◽  
Photometric Redshifts ◽  
Surface Mass ◽  
Dark Energy Survey ◽  
Galaxy Sample ◽  
Cosmic Voids ◽  
The Impact ◽  
Energy Survey

ABSTRACT What are the mass and galaxy profiles of cosmic voids? In this paper, we use two methods to extract voids in the Dark Energy Survey (DES) Year 1 redMaGiC galaxy sample to address this question. We use either 2D slices in projection, or the 3D distribution of galaxies based on photometric redshifts to identify voids. For the mass profile, we measure the tangential shear profiles of background galaxies to infer the excess surface mass density. The signal-to-noise ratio for our lensing measurement ranges between 10.7 and 14.0 for the two void samples. We infer their 3D density profiles by fitting models based on N-body simulations and find good agreement for void radii in the range 15–85 Mpc. Comparison with their galaxy profiles then allows us to test the relation between mass and light at the 10 per cent level, the most stringent test to date. We find very similar shapes for the two profiles, consistent with a linear relationship between mass and light both within and outside the void radius. We validate our analysis with the help of simulated mock catalogues and estimate the impact of photometric redshift uncertainties on the measurement. Our methodology can be used for cosmological applications, including tests of gravity with voids. This is especially promising when the lensing profiles are combined with spectroscopic measurements of void dynamics via redshift-space distortions.

scholarly journals Cosmological model parameter dependence of the matter power spectrum covariance from the DEUS-PUR Cosmo simulations

2020 ◽  
Vol 500 (2) ◽  
pp. 2532-2542
Author(s):  
Linda Blot ◽  
Pier-Stefano Corasaniti ◽  
Yann Rasera ◽  
Shankar Agarwal
Keyword(s):  
Dark Energy ◽  
Power Spectrum ◽  
Cold Dark Matter ◽  
Matter Density ◽  
Density Fluctuations ◽  
Matrix Analysis ◽  
Model Parameter ◽  
Matter Power Spectrum ◽  
Non Gaussian ◽  
The Impact

ABSTRACT Future galaxy surveys will provide accurate measurements of the matter power spectrum across an unprecedented range of scales and redshifts. The analysis of these data will require one to accurately model the imprint of non-linearities of the matter density field. In particular, these induce a non-Gaussian contribution to the data covariance that needs to be properly taken into account to realize unbiased cosmological parameter inference analyses. Here, we study the cosmological dependence of the matter power spectrum covariance using a dedicated suite of N-body simulations, the Dark Energy Universe Simulation–Parallel Universe Runs (DEUS-PUR) Cosmo. These consist of 512 realizations for 10 different cosmologies where we vary the matter density Ωm, the amplitude of density fluctuations σ8, the reduced Hubble parameter h, and a constant dark energy equation of state w by approximately $10{{\ \rm per\ cent}}$. We use these data to evaluate the first and second derivatives of the power spectrum covariance with respect to a fiducial Λ-cold dark matter cosmology. We find that the variations can be as large as $150{{\ \rm per\ cent}}$ depending on the scale, redshift, and model parameter considered. By performing a Fisher matrix analysis we explore the impact of different choices in modelling the cosmological dependence of the covariance. Our results suggest that fixing the covariance to a fiducial cosmology can significantly affect the recovered parameter errors and that modelling the cosmological dependence of the variance while keeping the correlation coefficient fixed can alleviate the impact of this effect.

Constraints on the Ricci dark energy cosmologies in Bianchi type I model

2021 ◽  
pp. 2150095
Author(s):  
H. Hossienkhani ◽  
N. Azimi ◽  
H. Yousefi
Keyword(s):  
Dark Energy ◽  
Dark Energy Model ◽  
Bianchi Type ◽  
Energy Model ◽  
Accelerated Expansion ◽  
Likelihood Method ◽  
Type I ◽  
Ricci Dark Energy ◽  
Bianchi Type I ◽  
The Impact

The impact of anisotropy on the Ricci dark energy cosmologies is investigated where it is assumed that the geometry of the universe is described by Bianchi type I (BI) metric. The main goal is to determine the astrophysical constraints on the model by using the current available data as type Ia supernovae (SNIa), the Baryon Acoustic Oscillation (BAO), and the Hubble parameter [Formula: see text] data. In this regard, a maximum likelihood method is applied to constrain the cosmological parameters. Combining the data, it is found out that the allowed range for the density parameter of the model stands in [Formula: see text]. With the help of the Supernova Legacy Survey (SNLS) sample, we estimate the possible dipole anisotropy of the Ricci dark energy model. Then, by using a standard [Formula: see text] minimization method, it is realized that the transition epoch from early decelerated to current accelerated expansion occurs faster in Ricci dark energy model than [Formula: see text]CDM model. The results indicate that the BI model for the Ricci dark energy is consistent with the observational data.

scholarly journals The impact of neutrino masses on the determination of dark energy properties

2007 ◽  
Vol 27 (5) ◽  
pp. 406-410 ◽  
Author(s):  
Axel De La Macorra ◽  
Alessandro Melchiorri ◽  
Paolo Serra ◽  
Rachel Bean
Keyword(s):  
Dark Energy ◽  
Neutrino Masses ◽  
The Impact

Corrected Article: Measure of the impact of future dark energy experiments based on discriminating power among quintessence models [Phys. Rev. D78, 043528 (2008)]

2008 ◽  
Vol 80 (12) ◽  
Author(s):  
Michael Barnard ◽  
Augusta Abrahamse ◽  
Andreas Albrecht ◽  
Brandon Bozek ◽  
Mark Yashar
Keyword(s):  
Dark Energy ◽  
Discriminating Power ◽  
The Impact

scholarly journals Impact of relativistic effects on the primordial non-Gaussianity signature in the large-scale clustering of quasars

2020 ◽  
Vol 499 (2) ◽  
pp. 2598-2607
Author(s):  
Mike (Shengbo) Wang ◽  
Florian Beutler ◽  
David Bacon
Keyword(s):  
Dark Energy ◽  
Power Spectrum ◽  
Luminosity Function ◽  
Large Scale ◽  
Relativistic Effects ◽  
Redshift Range ◽  
Cosmological Background ◽  
Relativistic Corrections ◽  
The Galaxy ◽  
The Impact

ABSTRACT Relativistic effects in clustering observations have been shown to introduce scale-dependent corrections to the galaxy overdensity field on large scales, which may hamper the detection of primordial non-Gaussianity fNL through the scale-dependent halo bias. The amplitude of relativistic corrections depends not only on the cosmological background expansion, but also on the redshift evolution and sensitivity to the luminosity threshold of the tracer population being examined, as parametrized by the evolution bias be and magnification bias s. In this work, we propagate luminosity function measurements from the extended Baryon Oscillation Spectroscopic Survey (eBOSS) to be and s for the quasar (QSO) sample, and thereby derive constraints on relativistic corrections to its power spectrum multipoles. Although one could mitigate the impact on the fNL signature by adjusting the redshift range or the luminosity threshold of the tracer sample being considered, we suggest that, for future surveys probing large cosmic volumes, relativistic corrections should be forward modelled from the tracer luminosity function including its uncertainties. This will be important to quasar clustering measurements on scales $k \sim 10^{-3}\, h\, {\rm Mpc}^{-1}$ in upcoming surveys such as the Dark Energy Spectroscopic Instrument (DESI), where relativistic corrections can overwhelm the expected fNL signature at low redshifts z ≲ 1 and become comparable to fNL ≃ 1 in the power spectrum quadrupole at redshifts z ≳ 2.5.

scholarly journals Dark Energy Survey Year 1 results: the impact of galaxy neighbours on weak lensing cosmology with im3shape

2017 ◽  
Vol 475 (4) ◽  
pp. 4524-4543 ◽  
Author(s):  
S Samuroff ◽  
S L Bridle ◽  
J Zuntz ◽  
M A Troxel ◽  
D Gruen ◽  
...  
Keyword(s):  
Dark Energy ◽  
Weak Lensing ◽  
Dark Energy Survey ◽  
The Impact ◽  
Energy Survey

Dynamical properties of scaling solutions in teleparallel dark energy cosmologies with nonminimal coupling

2017 ◽  
Vol 26 (09) ◽  
pp. 1750103 ◽  
Author(s):  
Mihai Marciu
Keyword(s):  
Dark Energy ◽  
Power Law ◽  
Scalar Fields ◽  
Teleparallel Gravity ◽  
Inverse Power ◽  
Coupling Coefficients ◽  
Potential Term ◽  
Inverse Power Law ◽  
The Stability ◽  
The Impact

The dynamical aspects of scaling solutions for the dark energy component in the theoretical framework of teleparallel gravity are considered, where dark energy is represented by a scalar field nonminimally coupled with the torsion and with a boundary term, where the boundary coupling term represents the divergence of the torsion vector. The behavior and stability of the scaling solutions are studied for scalar fields endowed with inverse power law potentials and with exponential potentials. It is shown that for scalar fields endowed with inverse power-law potentials, the stability conditions are not affected by the coupling coefficients. For the scalar fields endowed with exponential potentials, two cases are studied: at first, we have considered an infinitesimal deviation from the scaling solution in the corresponding Klein–Gordon equation, and the impact of distinct coupling coefficients on the stability of the solution are analyzed. Secondly, the potential-free case is considered where the dominance of the coupling terms over the potential term is analyzed, discussing the validity of the corresponding particular solution.

scholarly journals Manifestations of dark energy in the dynamics of the Solar system

2009 ◽  
Vol 5 (S264) ◽  
pp. 410-412
Author(s):  
Michal Křížek ◽  
Jan Brandts
Keyword(s):  
Dark Energy ◽  
Solar System ◽  
Hubble Constant ◽  
The Sun ◽  
Expansion Speed ◽  
Current Value ◽  
The Impact ◽  
The Universe

AbstractThe expansion speed of the Universe is increasing (Glanz 1998). This acceleration is attributed to dark energy which acts almost uniformly everywhere (including the Solar system) and thus essentially influences the Hubble constant. Its current value on a distance of 1 AU is H0 = 10 m/(yr AU). This is quite a large number and thus, the impact of dark energy should be detectable in the Solar system. We will illustrate it by several examples. Dark energy may partially be caused by gravitational aberration of the Sun, planets and other bodies.

scholarly journals Measure of the impact of future dark energy experiments based on discriminating power among quintessence models

2008 ◽  
Vol 78 (4) ◽  
Author(s):  
Michael Barnard ◽  
Augusta Abrahamse ◽  
Andreas Albrecht ◽  
Brandon Bozek ◽  
Mark Yashar
Keyword(s):  
Dark Energy ◽  
Discriminating Power ◽  
The Impact
Sign in / Sign up

Export Citation Format

Share Document