scholarly journals CMB temperature and matter power spectrum in a decay vacuum dark energy model

2011 ◽  
Vol 84 (12) ◽  
Author(s):  
Lixin Xu ◽  
Yuting Wang ◽  
Minglei Tong ◽  
Hyerim Noh
Keyword(s):  
Dark Energy ◽  
Power Spectrum ◽  
Dark Energy Model ◽  
Energy Model ◽  
Matter Power Spectrum ◽  
Cmb Temperature

scholarly journals Do we have any hope of detecting scattering between dark energy and baryons through cosmology?

2020 ◽  
Vol 493 (1) ◽  
pp. 1139-1152 ◽  
Author(s):  
Sunny Vagnozzi ◽  
Luca Visinelli ◽  
Olga Mena ◽  
David F Mota
Keyword(s):  
Dark Energy ◽  
Power Spectrum ◽  
Cross Sections ◽  
Direct Detection ◽  
Late Time ◽  
Temperature Anisotropy ◽  
Momentum Exchange ◽  
Microwave Background ◽  
Matter Power Spectrum ◽  
Cmb Temperature

ABSTRACT We consider the possibility that dark energy and baryons might scatter off each other. The type of interaction we consider leads to a pure momentum exchange, and does not affect the background evolution of the expansion history. We parametrize this interaction in an effective way at the level of Boltzmann equations. We compute the effect of dark energy-baryon scattering on cosmological observables, focusing on the cosmic microwave background (CMB) temperature anisotropy power spectrum and the matter power spectrum. Surprisingly, we find that even huge dark energy-baryon cross-sections $\sigma _{xb} \sim {\cal O}({\rm b})$, which are generically excluded by non-cosmological probes such as collider searches or precision gravity tests, only leave an insignificant imprint on the observables considered. In the case of the CMB temperature power spectrum, the only imprint consists in a sub-per cent enhancement or depletion of power (depending whether or not the dark energy equation of state lies above or below −1) at very low multipoles, which is thus swamped by cosmic variance. These effects are explained in terms of differences in how gravitational potentials decay in the presence of a dark energy-baryon scattering, which ultimately lead to an increase or decrease in the late-time integrated Sachs–Wolfe power. Even smaller related effects are imprinted on the matter power spectrum. The imprints on the CMB are not expected to be degenerate with the effects due to altering the dark energy sound speed. We conclude that, while strongly appealing, the prospects for a direct detection of dark energy through cosmology do not seem feasible when considering realistic dark energy-baryon cross-sections. As a caveat, our results hold to linear order in perturbation theory.

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.

scholarly journals Cosmological viable f(R,T) dark energy model: dynamics and stability

2014 ◽  
Vol 356 (1) ◽  
pp. 173-180 ◽  
Author(s):  
E. H. Baffou ◽  
A. V. Kpadonou ◽  
M. E. Rodrigues ◽  
M. J. S. Houndjo ◽  
J. Tossa
Keyword(s):  
Dark Energy ◽  
Dark Energy Model ◽  
Energy Model ◽  
Model Dynamics

scholarly journals f(T) GRAVITY FROM HOLOGRAPHIC RICCI DARK ENERGY MODEL WITH NEW BOUNDARY CONDITIONS

2013 ◽  
Vol 28 (39) ◽  
pp. 1350171 ◽  
Author(s):  
PENG HUANG ◽  
YONG-CHANG HUANG ◽  
FANG-FANG YUAN
Keyword(s):  
Dark Energy ◽  
Boundary Conditions ◽  
Dark Energy Model ◽  
Energy Model ◽  
Ricci Dark Energy ◽  
Expected Information ◽  
Better Than

Commonly used boundary conditions in reconstructing f(T) gravity from holographic Ricci dark energy (RDE) model are found to cause some problem, we therefore propose new boundary conditions in this paper. By reconstructing f(T) gravity from the RDE with these new boundary conditions, we show that the new ones are better than the present commonly used ones since they can give the physically expected information, which is lost when the commonly used ones are taken in the reconstruction, of the resulting f(T) theory. Thus, the new boundary conditions proposed here are more suitable for the reconstruction of f(T) gravity.

scholarly journals Quadrature algorithms to the luminosity distance with a time-dependent dark energy model

2011 ◽  
Vol 2011 (11) ◽  
pp. 047-047 ◽  
Author(s):  
Nan-Nan Yue ◽  
De-Zi Liu ◽  
Xiao-Xing Pei ◽  
Fang-Fang Zhu ◽  
Tong-Jie Zhang ◽  
...  
Keyword(s):  
Dark Energy ◽  
Dark Energy Model ◽  
Energy Model ◽  
Time Dependent ◽  
Luminosity Distance
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