Alexander Wiegand (Albert-Einstein-Institut)

Minkowski functionals of the SDSS Luminous red galaxies
When Apr 30, 2013 from 11:00 AM to 12:00 PM
What
  • Special Seminar
Where SH, Lecture hall
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In this talk, we present the results of our Minkowski functional analysis of the structure of the galaxy distribution in the luminous red galaxy (LRG) sample of the Sloan Digital Sky Survey. With the discovery of larger and larger coherent structures, it is worthwhile to test the consistency of the observations with the standard models of structure formation. For this purpose, Minkowski functionals are very useful, as they contain more information than the usual two point statistics. For the analysis, we use Minkowski functionals in the boolean grain model, that allows a very precise and robust comparison. In addition, the Minkowski functionals in this model may be analytically related to a series of the (higher order) correlation functions of the distribution. This allows us to quantify the influence of higher order clustering beyond the simple two point correlations.

Comparing the observed Minkowski functionals to the functionals obtained from a set of N-body simulations, we find them basically consistent with each other. Expanding the functionals into a power series of integrals over n-point functions and comparing the coefficients with the theoretical prediction, gives also a consistent picture. Finally, we use the series expansion to investigate the importance of the higher order n-point functions for the shape of the functionals.