Cosmological density fluctuations and large-scale structure From N-point correlation functions to the probability distribution

1985 ◽  
Vol 289 ◽  
pp. 10 ◽  
Author(s):  
J. N. Fry
Keyword(s):  
Probability Distribution ◽  
Correlation Functions ◽  
Large Scale ◽  
Large Scale Structure ◽  
Density Fluctuations ◽  
Scale Structure ◽  
Point Correlation

scholarly journals The Forest of Absorption Lines in QSO Spectra - A Key to the Large Scale Structure Development?

1987 ◽  
Vol 121 ◽  
pp. 337-339
Author(s):  
J. P. Mücket ◽  
V. Müller
Keyword(s):  
High Resolution ◽  
Correlation Analysis ◽  
Correlation Functions ◽  
Large Scale ◽  
Large Scale Structure ◽  
Scale Structure ◽  
Absorption Lines ◽  
Structure Development ◽  
Point Correlation ◽  
Quasiperiodic Structure

For six published high resolution QSO spectra a correlation analysis of unidentified absorption lines is performed. The two-point correlation functions typically show some quasiperiodic structure. The results allow for the interpretation that absorbing clouds lie in sheetlike structures as predicted by the pancake theory.

scholarly journals Large Scale Structure of the Universe

1998 ◽  
Vol 179 ◽  
pp. 317-328 ◽  
Author(s):  
N.A. Bahcall
Keyword(s):  
Large Scale ◽  
Initial Conditions ◽  
Large Scale Structure ◽  
Density Fluctuations ◽  
Scale Structure ◽  
Sloan Digital Sky Survey ◽  
Sky Survey ◽  
Initial Spectrum ◽  
Formation And Evolution ◽  
The Universe

How is the universe organized on large scales? How did this structure evolve from the unknown initial conditions of a rather smooth early universe to the present time? The answers to these questions will shed light on the cosmology we live in, the amount, composition and distribution of matter in the universe, the initial spectrum of density fluctuations that gave rise to this structure, and the formation and evolution of galaxies, lusters of galaxies, and larger scale structures.To address these fundamental questions, large and accurate sky surveys are needed—in various wavelengths and to various depths. In this presentation I review current observational studies of large scale structure, present the constraints these observations place on cosmological models and on the amount of dark matter in the universe, and highlight some of the main unsolved problems in the field of large-scale structure that could be solved over the next decade with the aid of current and future surveys. I briefly discuss some of these surveys, including the Sloan Digital Sky Survey that will provide a complete imaging and spectroscopic survey of the high-latitude northern sky, with redshifts for the brightest ∼ 106 galaxies, 105 quasars, and 103.5 rich clusters of galaxies. The potentialities of the SDSS survey, as well as of cross-wavelength surveys, for resolving some of the unsolved problems in large-scale structure and cosmology are discussed.

The Local Large-Scale Structure from HIPASS

2005 ◽  
Vol 216 ◽  
pp. 196-202
Author(s):  
Martin Zwaan ◽  
Martin Meyer ◽  
Rachel Webster ◽  
Lister Staveley-Smith
Keyword(s):  
Large Scale ◽  
Large Scale Structure ◽  
Scale Structure ◽  
Sky Survey ◽  
The Galaxy ◽  
Point Correlation ◽  
Point Correlation Function ◽  
Fisher Relation ◽  
Galaxy Population ◽  
Mass Functions

The HI Parkes All Sky Survey (HIPASS) offers a unique perspective on the galaxy population in the local universe. A catalogue of 4315 HI-selected galaxies has been extracted from the southern region of the survey (δ < +2°). This catalogue gives a clear view of the local large-scale structure and is used to study the two-point correlation function, the Tully-Fisher relation, and galaxy luminosity and mass functions. Some initial results are discussed here.

scholarly journals Constraints on neutrino masses from the study of the nearby large-scale structure and galaxy cluster counts

2016 ◽  
Vol 31 (21) ◽  
pp. 1640008 ◽  
Author(s):  
Hans Böhringer ◽  
Gayoung Chon
Keyword(s):  
Large Scale ◽  
Cosmological Parameters ◽  
Large Scale Structure ◽  
Matter Density ◽  
Density Fluctuations ◽  
Scale Structure ◽  
Neutrino Masses ◽  
Microwave Background ◽  
X Ray ◽  
Massive Neutrinos

The high precision measurements of the cosmic microwave background by the Planck survey yielded tight constraints on cosmological parameters and the statistics of the density fluctuations at the time of recombination. This provides the means for a critical study of structure formation in the Universe by comparing the microwave background results with present epoch measurements of the cosmic large-scale structure. It can reveal subtle effects such as how different forms of Dark Matter may modify structure growth. Currently most interesting is the damping effect of structure growth by massive neutrinos. Different observations of low redshift matter density fluctuations provided evidence for a signature of massive neutrinos. Here we discuss the study of the cosmic large-scale structure with a complete sample of nearby, X-ray luminous clusters from our REFLEX cluster survey. From the observed X-ray luminosity function and its reproduction for different cosmological models, we obtain tight constraints on the cosmological parameters describing the matter density, [Formula: see text], and the density fluctuation amplitude, [Formula: see text]. A comparison of these constraints with the Planck results shows a discrepancy in the framework of a pure [Formula: see text]CDM model, but the results can be reconciled, if we allow for a neutrino mass in the range of 0.17 eV to 0.7 eV. Also some others, but not all of the observations of the nearby large-scale structure provide evidence or trends for signatures of massive neutrinos. With further improvement in the systematics and future survey projects, these indications will develop into a definitive measurement of neutrino masses.

scholarly journals On soft limits of large-scale structure correlation functions

2015 ◽  
Vol 2015 (02) ◽  
pp. 026-026 ◽  
Author(s):  
Ido Ben-Dayan ◽  
Thomas Konstandin ◽  
Rafael A. Porto ◽  
Laura Sagunski
Keyword(s):  
Correlation Functions ◽  
Large Scale ◽  
Large Scale Structure ◽  
Scale Structure ◽  
Structure Correlation

CHAOTIC INFLATIONARY UNIVERSE AND THE ANISOTROPY OF THE LARGE-SCALE STRUCTURE

1990 ◽  
Vol 05 (13) ◽  
pp. 2625-2646 ◽  
Author(s):  
G. V. CHIBISOV ◽  
YU. V. SHTANOV
Keyword(s):  
Correlation Function ◽  
Large Scale ◽  
Large Scale Structure ◽  
Expected Value ◽  
Scale Structure ◽  
Inflationary Universe ◽  
Point Correlation ◽  
Point Correlation Function ◽  
Inflation Scenario ◽  
Chaotic Inflation

In frames of the chaotic inflation scenario the influence of the inhomogeneity of the inflationary universe on the primordial fluctuations spectrum is investigated. The phenomenon of the anisotropy of the observed large-scale structure is predicted. In particular this means that the two-point correlation function ξ(x) is anisotropic. An expected value of the anisotropy is about 10%. The observation of the anisotropy predicted could serve as confirmation to the chaotic inflation scenario.

scholarly journals N-Body Simulation of Large Scale Structure in the Universe with Oscillating Scalar Field

1999 ◽  
Vol 183 ◽  
pp. 252-252
Author(s):  
K. Kawabata ◽  
H. Taguchi ◽  
Y. Andoh
Keyword(s):  
Scalar Field ◽  
Large Scale ◽  
Large Scale Structure ◽  
Scale Structure ◽  
Homogeneous Distribution ◽  
Coupling Constant ◽  
Mesh Method ◽  
Point Correlation ◽  
Point Correlation Function ◽  
The Universe

Using the particle-mesh method with 1283 grids and 643 particles, we have carried out a number of N-body simulations of the large scale structure for the cosmological model proposed by Fukuyama et al.(1996): this model contains the matter(Ω0) as well as a scalar field(Φ) with a finite mass that couples non-minimally with the scalar curvature R through the form of 1/2ηΦ2R, where η(= −80) is the coupling constant.For simplicity, we have adopted the same values as those employed by Fukuyama et al.(1996) for all the parameters other than Ω0, fo which we have varied from 0.001 to 0.15. In performing our simulation, we further assume that only the density of matter ρ spatially fluctuates. The initial condition is created by perturbing the homogeneous distribution of the particles by means of the random Gaussian Harrison-Zeldovich spectrum.The two-point correlation function ξ(r) is then compputed for each of the resulting structures to compare with the observational data(Davis and Peebles, 1983). It is interesting to note that the structure formation appears to be achieved rather straightforwardly with the scalar field model. However, in order to yield an agreement between the theoretical and the observational two-point correlation functions, we seem to require the Ω0 value much larger than 0.01 adopted by Fukuyama et al.(1996).

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