scholarly journals Matter bispectrum of large-scale structure: Three-dimensional comparison between theoretical models and numerical simulations

2016 ◽  
Vol 93 (8) ◽  
Author(s):  
Andrei Lazanu ◽  
Tommaso Giannantonio ◽  
Marcel Schmittfull ◽  
E. P. S. Shellard
Keyword(s):  
Numerical Simulations ◽  
Large Scale ◽  
Three Dimensional ◽  
Theoretical Models ◽  
Large Scale Structure ◽  
Scale Structure

scholarly journals Inferring high-redshift large-scale structure dynamics from the Lyman-α forest

2019 ◽  
Vol 630 ◽  
pp. A151 ◽  
Author(s):  
Natalia Porqueres ◽  
Jens Jasche ◽  
Guilhem Lavaux ◽  
Torsten Enßlin
Keyword(s):  
Large Scale ◽  
High Redshift ◽  
Three Dimensional ◽  
Large Scale Structure ◽  
Scale Structure ◽  
Modal Parameter ◽  
Large Scale Structures ◽  
Quasar Spectra ◽  
Large Scale Flow ◽  
Fully Bayesian

One of the major science goals over the coming decade is to test fundamental physics with probes of the cosmic large-scale structure out to high redshift. Here we present a fully Bayesian approach to infer the three-dimensional cosmic matter distribution and its dynamics at z >  2 from observations of the Lyman-α forest. We demonstrate that the method recovers the unbiased mass distribution and the correct matter power spectrum at all scales. Our method infers the three-dimensional density field from a set of one-dimensional spectra, interpolating the information between the lines of sight. We show that our algorithm provides unbiased mass profiles of clusters, becoming an alternative for estimating cluster masses complementary to weak lensing or X-ray observations. The algorithm employs a Hamiltonian Monte Carlo method to generate realizations of initial and evolved density fields and the three-dimensional large-scale flow, revealing the cosmic dynamics at high redshift. The method correctly handles multi-modal parameter distributions, which allow constraining the physics of the intergalactic medium with high accuracy. We performed several tests using realistic simulated quasar spectra to test and validate our method. Our results show that detailed and physically plausible inference of three-dimensional large-scale structures at high redshift has become feasible.

scholarly journals Erratum: Three-dimensional hydrodynamical simulations of the large-scale structure of W50-SS433

2008 ◽  
Vol 389 (2) ◽  
pp. 1008-1008 ◽  
Author(s):  
Jesús Zavala ◽  
Pablo F. Velázquez ◽  
Adriano H. Cerqueira ◽  
Gloria M. Dubner
Keyword(s):  
Large Scale ◽  
Three Dimensional ◽  
Large Scale Structure ◽  
Scale Structure ◽  
Hydrodynamical Simulations

Three-dimensional simulation of large-scale structure in the Universe

Nature ◽  
1983 ◽  
Vol 305 (5931) ◽  
pp. 196-198 ◽  
Author(s):  
Joan Centrella ◽  
Adrian L. Melott
Keyword(s):  
Large Scale ◽  
Three Dimensional ◽  
Large Scale Structure ◽  
Scale Structure ◽  
Dimensional Simulation ◽  
The Universe

scholarly journals Extragalactic filament detection with a layer smoothing method

2014 ◽  
Vol 4 (1-2) ◽  
pp. 42-45 ◽  
Author(s):  
A. Tugay
Keyword(s):  
Numerical Simulations ◽  
Large Scale ◽  
Large Scale Structure ◽  
Density Field ◽  
Scale Structure ◽  
Smoothing Method ◽  
Computer Algorithms ◽  
The Real

Filaments are clearly visible in galaxy distributions, but they are difficult to detect by computer algorithms. Most methods of filament detection can be used only with numerical simulations of a large-scale structure. New simple and effective methods for the real filament detection should be developed. The method of a smoothed galaxy density field was applied in this work to SDSS data of galaxy positions. Five concentric radial layers of 100 Mpc are appropriate for filaments detection. Two methods were tested for the first layer and one more method is proposed.

scholarly journals Mapping the Large-Scale Structure

1994 ◽  
Vol 161 ◽  
pp. 669-686
Author(s):  
V. de Lapparent
Keyword(s):  
Large Scale ◽  
Background Radiation ◽  
Theoretical Models ◽  
Large Scale Structure ◽  
Scale Structure ◽  
Nearby Galaxy ◽  
Redshift Surveys ◽  
Galaxy Distribution ◽  
The Galaxy ◽  
Microwave Background Radiation

The nearby galaxy distribution suggests a remarkable structure in which large voids are delineated by dense walls of galaxies in a cell-like pattern. The nearby voids range in diameter from ∼ 10 to ∼ 50h− 1 Mpc. Deeper surveys appear to be consistent with the nearby distribution and show no evidence of voids larger than ∼ 100h −1 ∗ Mpc. We might thus have reached the scale where the universe becomes homogeneous. The size of the largest inhomogeneities in the galaxy distribution is an important issue because it can put tight constraints on the theoretical models when confronted by the high degree of isotropy of the microwave background radiation. Comparison of the various existing redshift surveys emphasizes the need for systematic redshift surveys over significant areas of the sky out to intermediate and large distances. Although deep pencil-beam surveys are best suited for probing a large number of voids and walls, understanding the nature of the intercepted peaks and valleys in terms of large-scale structure requires that the angular coverage of the surveys be larger than the galaxy auto-correlation length. If this condition is not satisfied, the size of the voids and the density contrast of the walls can be overestimated.

scholarly journals Automatic Three-Dimensional Measurement of Large-Scale Structure Based on Vision Metrology

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Zhaokun Zhu ◽  
Banglei Guan ◽  
Xiaohu Zhang ◽  
Daokui Li ◽  
Qifeng Yu
Keyword(s):  
Large Scale ◽  
Three Dimensional ◽  
Large Scale Structure ◽  
Scale Structure ◽  
Blob Detection ◽  
Three Dimensional Measurement ◽  
Fully Automatic ◽  
Voting Strategy ◽  
Key Techniques

All relevant key techniques involved in photogrammetric vision metrology for fully automatic 3D measurement of large-scale structure are studied. A new kind of coded target consisting of circular retroreflective discs is designed, and corresponding detection and recognition algorithms based on blob detection and clustering are presented. Then a three-stage strategy starting with view clustering is proposed to achieve automatic network orientation. As for matching of noncoded targets, the concept of matching path is proposed, and matches for each noncoded target are found by determination of the optimal matching path, based on a novel voting strategy, among all possible ones. Experiments on a fixed keel of airship have been conducted to verify the effectiveness and measuring accuracy of the proposed methods.

scholarly journals Radio Surveys and Large Scale Structure

1991 ◽  
Vol 44 (6) ◽  
pp. 759 ◽  
Author(s):  
PA Shaver
Keyword(s):  
Radio Source ◽  
Large Scale ◽  
Three Dimensional ◽  
Large Scale Structure ◽  
Radio Galaxies ◽  
Scale Structure ◽  
Radio Sources ◽  
Clusters Of Galaxies ◽  
Normal Galaxies ◽  
Dimensional Distribution

An analysis of the Molonglo Reference Catalogue indicates that significant departures from isotropy are present in the sky distribution of strong extragalactic radio sources. This has been shown to be due to local large scale structure, specifically a concentration to the supergalactic plane, which also influences the slope of the source counts. A study of the three-dimensional distribution of local radio galaxies shows that they are more strongly concentrated to the supergalactic plane than are optically�selected galaxies, and that the supergalactic concentration is more extensive than hitherto believed. It appears that radio galaxies (and clusters of galaxies) trace the 'skeleton' of large scale structure, about which normal galaxies are more loosely distributed. Thus, while large scale structure evidently complicates the interpretation of radio source counts, it appears that radiO surveys can be of value in exploring structures on the largest scales.

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