scholarly journals Quantifying the Cosmic Web using the Shapefinder diagonistic

2014 ◽  
Vol 11 (S308) ◽  
pp. 250-253
Author(s):  
Prakash Sarkar
Keyword(s):  
Gaussian Curvature ◽  
Mean Curvature ◽  
Large Scale ◽  
Large Scale Structure ◽  
Discrete Data ◽  
Scale Structure ◽  
Data Sets ◽  
Polyhedral Surface ◽  
Minkowski Functionals ◽  
And Topology

AbstractOne of the most successful method in quantifying the structures in the Cosmic Web is the Minkowski Functionals. In 3D, there are four minkowski Functionals: Area, Volume, Integrated Mean Curvature and the Integrated Gaussian Curvature. For defining the Minkowski Functionals one should define a surface. We have developed a method based on Marching cube 33 algorithm to generate a surface from a discrete data sets. Next we calculate the Minkowski Functionals and Shapefinder from the triangulated polyhedral surface. Applying this methodology to different data sets , we obtain interesting results related to geometry, morphology and topology of the large scale structure

The Large Scale Structure Peak as a Comoving Standard Ruler

2005 ◽  
Vol 201 ◽  
pp. 388-391
Author(s):  
Boudewijn F. Roukema ◽  
Gary A. Mamon
Keyword(s):  
Large Scale ◽  
Large Scale Structure ◽  
Scale Structure ◽  
Data Sets ◽  
Density Parameter ◽  
Observable Universe ◽  
Standard Candle ◽  
Type Ia ◽  
Density Perturbations ◽  
Empirical Standard

Estimates of the curvature parameters Ω0 (density parameter) and Δ0 (cosmological constant) can be made geometrically by use of either a standard candle or a standard ruler. Just as supernovae of Type Ia appear to provide a good empirical standard candle, it now appears observationally justified to use the peak in the power spectrum of density perturbations at L ≍ 130±10h-1 Mpc as an empirical standard rod. It will be shown that voids of this size are traced by quasars in a homogeneous catalogue near the South Galactic Pole at z ˜ 2 and that the large scale structure peak of the catalogue constrains the value of Ω0 to 0.1 < Ω0 < 0.45 (68% confidence), independently of Δ0. Combination with the supernovae Ia data is sufficient to show that the observable Universe is almost flat. In other words, the combination of a standard ruler and a standard candle detected in two presently available data sets is sufficient to show that the Universe is nearly flat, independently of any microwave background data or any other data analyses.

Sign in / Sign up

Export Citation Format

Share Document