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Related papers: Mixed Models with n>1 and Large Scale Structure co…

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We compute CBR anisotropies in mixed models with different hot components, including neutrinos or volatile HDM arising from the decay of heavier particles. The CBR power spectra of these models exhibit a higher doppler peak than CDM, and…

Astrophysics · Physics 2009-10-30 E. Pierpaoli , S. A. Bonometto

We study linear power spectra and formation of large scale structures in flat cosmological models with $\Lambda \ge 0$ and cold plus hot dark matter components (MLM). The hot component consists of massive neutrinos with cosmological density…

Astrophysics · Physics 2007-05-23 R. Valdarnini , T. Kahniashvili , B. Novosyadlyj

The abundance of galactic systems at high redshifts can impose a strong constraint on the cold+hot dark matter (CDM+HDM) models. The hot component reduces the excessive small-scale power in the COBE-normalized CDM model but also delays the…

Astrophysics · Physics 2009-10-22 Chung-Pei Ma , Edmund Bertschinger

If the hot, X-ray emitting gas in rich clusters forms a fair sample of the universe (as in Cold Dark Matter (CDM) models), and the universe is at the critical density, $\Omega_T = 1$, then the data appears to imply a baryon fraction,…

Astrophysics · Physics 2009-10-28 Russell W. Strickland , David N. Schramm

Cosmological models with a positive cosmological constant and $\Omega_0<1$ have a number of attractive features. A larger Hubble constant, which can be compatible with the recent HST estimate, and a large fraction of baryon density in…

Astrophysics · Physics 2007-05-23 Anatoly Klypin , Joel Primack , Jon Holtzman

We discuss variants of Cold Dark Matter (CDM) dominated cosmological models that give good agreement with a range of observations. We consider models with hot dark matter, tilt, $\Omega < 1$, or a cosmological constant. We also discuss the…

Astrophysics · Physics 2007-05-23 Rachel S. Somerville , Joel R. Primack

Models for structure formation attempt to predict the power spectrum of density perturbations in the present universe from the initial power spectrum and the nature of dark matter. Observational constraints on the power spectrum at…

Astrophysics · Physics 2007-05-23 K. Subramanian , T. Padmanabhan

We present an analysis of cosmological models with mixed dark matter (spectrum slope of density perturbations $n_S \in [0.6, 1.6]$, hot dark matter abundance $\Omega_\nu \in [0.0, 0.6]$) in spatially flat Universe, based on Press-Schechter…

Astrophysics · Physics 2011-04-15 N. A. Arkhipova , V. N. Lukash , E. V. Mikheeva

We study the clustering of the mass distribution in COBE-normalized open and flat CDM models using large N-body simulations. With an age of the universe of 14 Gyr (12 Gyr) for the flat (open) models and a baryon density fixed by…

Astrophysics · Physics 2015-06-24 Shaun Cole , David H. Weinberg , Carlos S. Frenk , Bharat Ratra

Fluctuations in the CMB have now been detected over a wide range of angular scales, and a consistent picture seems to be emerging. The data cannot currently constrain a large number of cosmological parameters, but it is clear that there is…

Astrophysics · Physics 2009-09-25 Douglas Scott , Martin White

The time evolution of the number density of galaxy clusters and their mass and temperature functions are used to constrain cosmological parameters in the spatially flat dark matter models containing a fraction of hot particles (massive…

Astrophysics · Physics 2009-11-07 N. A. Arhipova , T. Kahniashvili , V. N. Lukash

Since the baryon-to-photon ratio "eta" is in some doubt at present, we ignore the constraints on eta from big bang nucleosynthesis (BBN) and fit the three key cosmological parameters (h, Omega_M, eta) to four other observational…

Astrophysics · Physics 2022-03-23 G. Steigman , N. Hata , J. E. Felten

We present constraints on the parameters of the $\Lambda$CDM cosmological model in the presence of massive neutrinos, using the one-dimensional Ly$\alpha$ forest power spectrum obtained with the Baryon Oscillation Spectroscopic Survey…

We use observational data on the large scale structure (LSS) of the Universe measured over a wide range of scales from sub-galactic up to horizon scale and on the cosmic microwave background anisotropies to determine cosmological parameters…

Astrophysics · Physics 2011-07-19 R. Durrer , B. Novosyadlyj

We investigate a scalar field dark energy model (i.e., $\phi$CDM model) with massive neutrinos, where the scalar field possesses an inverse power-law potential, i.e., $V(\phi)\propto {\phi}^{-\alpha}$ ($\alpha>0$). We find that the sum of…

Cosmology and Nongalactic Astrophysics · Physics 2015-12-14 Yun Chen , Lixin Xu

We consider unified dark sector models in which the fluid can collapse and cluster into halos, allowing for hierarchical structure formation to proceed as in standard cosmology. We show that both background evolution and linear…

Cosmology and Nongalactic Astrophysics · Physics 2025-02-05 Mahmoud Hashim , Amr El-Zant

Recent results have suggested that the density of baryons in the Universe, OmegaB, is much more uncertain than previously thought, and may be significantly higher. We demonstrate that a higher OmegaB increases the viability of…

Astrophysics · Physics 2015-06-24 Martin White , Pedro T. P. Viana , Andrew R. Liddle , Douglas Scott

The mixed cold-hot dark matter cosmological model (CHDM) with $\Omega_{tot}=1$ and a falling power-law initial spectrum of Gaussian adiabatic perturbations ($n>1$) is tested using recent obserbational data. It is shown that its fit to the…

Astrophysics · Physics 2009-10-22 Dmitri Pogosyan , Alexei Starobinsky

The standard cosmological model, LCDM, provides an excellent fit to Cosmic Microwave Background (CMB) data. However, the model has well known problems. For example, the cosmological constant, is fine-tuned to 1 part in 10^100 and the cold…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-18 T. Shanks , R. W. F. Johnson , J. A. Schewtschenko , J. R. Whitbourn

The cold dark matter (CDM) model of structure formation, normalized on large scales, leads to excessive pairwise velocity dispersions on small scales. In an attempt to circumvent this problem, we study three scenarios (all with $\Omega=1$)…

High Energy Physics - Phenomenology · Physics 2009-10-22 James. M. Gelb , Ben-Ami Gradwohl , Joshua A. Frieman
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