Topology of large-scale structure in the early universe (Or searching for voids in the Lyman-alpha forest)

1988 ◽  
Vol 100 ◽  
pp. 1331
Author(s):  
Arlin Crotts
2020 ◽  
Vol 46 (6) ◽  
pp. 359-369
Author(s):  
M. I. Demiański ◽  
A. G. Doroshkevich ◽  
T. I. Larchenkova

1990 ◽  
Vol 43 (2) ◽  
pp. 159
Author(s):  
E Saar

Implications of the observed large scale structure on the physics of the early universe are described. A short review of Soviet work on the subject is given, and the present status of the fractal model of the large scale structure is discussed.


1988 ◽  
Vol 130 ◽  
pp. 553-553
Author(s):  
Y.-Z. Liu ◽  
Z.-G. Deng

We have suggested a scenario of fractal turbulence which might explain the origin of galaxies and the observed large scale structure of the universe (Liu and Deng, 1987). Under the condition of the early universe, the cosmic fluid can be regarded as incompressible. If we assume that the density perturbations in the early universe are adiabatic and have the scale-free Zeldovich spectrum, we may obtain the spectrum of the velocity perturbations. Perturbations with scales less than horizon will undergo dissipative process by Thomson scattering. So, the cosmic fluid can be considered as a viscous fluid (Peebles, 1971). We can find the largest and smallest scale of the perturbations in the cosmic fluid by taking account of the Reynold's number on given scale and the scale of horizon. Using the present values of Hubble constant and the mean density of matter, we have found that on the scale of horizon the Reynold's number is just the order of 102. This result shows that perturbations with scale a little smaller than horizon may produce Karman vortices before recombination and the vortices might form fractal turbulence due to Thomson drag.


2012 ◽  
Vol 12 ◽  
pp. 100-109 ◽  
Author(s):  
JAAN EINASTO

An overview is given on properties of the Large Scale Structure (LSS) using recent sky surveys (SDSS Main sample). LSS evolves very slowly, thus it contains imprints of physical conditions in the early Universe, as well as processes during its evolution. Present physical experiments are still unable to reproduce conditions in the very early Universe, thus the study of the properties of the LSS yields valuable information for fundamental physics.


2020 ◽  
Vol 642 ◽  
pp. L1
Author(s):  
Marco Mignoli ◽  
Roberto Gilli ◽  
Roberto Decarli ◽  
Eros Vanzella ◽  
Barbara Balmaverde ◽  
...  

We report on the spectroscopic confirmation of a large-scale structure around the luminous z = 6.31 quasi-stellar object (QSO) SDSS J1030+0524, powered by a one billion solar mass black hole. The structure is populated by at least six members, namely, four Lyman-break galaxies (LBGs), and two Lyman alpha emitters (LAEs). The four LBGs were identified among a sample of 21 i-band dropouts with zAB <  25.5 selected up to projected separations of 5 physical Mpc (15 arcmin) from the QSO. Their redshifts were determined through multi-object spectroscopic observations at 8−10 m class telescopes lasting up to eight hours. The two LAEs were identified in a 6 h VLT/MUSE observation centered on the QSO. The redshifts of the six galaxies cover the range between 6.129−6.355. Assuming that the peculiar velocities are negligible, this range corresponds to radial separations of ±5 physical Mpc from the QSO, that is comparable to the projected scale of the observed LBG distribution on the sky. We conservatively estimate that this structure is significant at a level > 3.5σ and that the level of the galaxy overdensity is at least 1.5−2 within the large volume sampled (∼780 physical Mpc3). The spectral properties of the six member galaxies (Lyα strength and UV luminosity) are similar to those of field galaxies at similar redshifts. This is the first spectroscopic identification of a galaxy overdensity around a supermassive black hole in the first billion years of the Universe. Our finding lends support to the idea that the most distant and massive black holes form and grow within massive (>1012 M⊙) dark matter halos in large-scale structures and that the absence of earlier detections of such systems is likely due to observational limitations.


2008 ◽  
Vol 23 (17n20) ◽  
pp. 1695-1706 ◽  
Author(s):  
DAI G. YAMAZAKI ◽  
KIYOTOMO ICHIKI ◽  
KAJINO TOSHITAKA ◽  
GRANT J. MATHEWS

The existence of a primordial magnetic field (PMF) would affect both the temperature and polarization anisotropies of the cosmic microwave background (CMB) and the formation of the large scale structure(LSS). It also provides a plausible explanation for the disparity between observations and theoretical fits to the CMB power spectrum and the LSS. Here we report on calculations of not only the numerical power spectrum of the PMF, but also the correlations between the PMF power spectrum and the primary curvature perturbations.


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