Browsing by Subject "twopoint correlation function"
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(2020)The distribution of matter in space is not homogeneous. Large structures such as galaxy groups, clusters or big empty spaces called voids can be observed at large scales in the Universe. The large scale structure of the Universe will depend on both the cosmological parameters and the dynamics of galaxy formation and evolution. One of the main observables that allow us to quantify this structure is the twopoint correlation function, with which we can trace different galaxy properties such as luminosity, stellar mass and also, it enables us to track its evolution with redshift. In galaxy surveys, we do not obtain the location of galaxies in real space. We obtain our data in what it is called redshift space. This redshift space can be defined as a distortion of the real space generated by the redshift introduced by the peculiar velocities of galaxies and from the Hubble expansion of the Universe. Therefore, the distribution of galaxies in redshift space will look different from the one obtained in real space. These differences between both spaces are small but not negligible, and they depend strictly on the cosmology. In this work, we will assume a ΛCDM cosmology. Therefore, in order to find the different 1dimensional or 2dimensional correlations functions, we will use the most updated version of the code provided by the Euclid consortium, which belongs officially to the ESA Euclid mission. Moreover, we will also need different galaxy catalogues. These catalogues have already been simulated and they are called Minerva mocks, which are a set of 300 different cosmological mocks produced with Nbody simulations. Finally, as there is a welldefined relation between real and redshift space, one could also assume that there is a relation between the twopoint correlation functions in both real and redshift space. In this project, we will prove that the realspace onedimensional twopoint correlation function, which is the physically meaningful one, can be derived from the twodimensional twopoint correlation function in redshift space following a geometrical procedure independent of approximations. This method, in theory, should work for all distance scales.
Now showing items 11 of 1