ANGULAR POWER SPECTRA OF LARGE SCALE STRUCTURES IN THE CONTEXT OF WIDE PHOTOMETRIC SURVEYS
| Autor: | Neveu, J., Campagne, J.E., Plaszczynski, S. |
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| Přispěvatelé: | Laboratoire de l'Accélérateur Linéaire (LAL), Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11) |
| Jazyk: | angličtina |
| Rok vydání: | 2018 |
| Předmět: | |
| Zdroj: | 53rd Rencontres de Moriond on Cosmology 53rd Rencontres de Moriond on Cosmology, Mar 2018, La Thuile, Italy. pp.79-82 |
| Popis: | International audience; The statistical distribution of galaxies is a powerful probe to constraincosmological and gravity models. In particular the matter power spectrum P (k)brings information about the cosmological distance evolution and the galaxyclustering. However the building of P (k) from galaxy catalogues needs acosmological model to convert angles on the sky and redshifts into distances,which leads to difficulties when comparing data with predicted P (k) from othercosmological models. The angular power spectrum C(z1, z2) between two binslocated at redshift z1 and z2 contains the same kind of information than thematter power spectrum but is free from any cosmological assumption. However, theprediction of C(z1, z2) from P (k) is a costly computation when performedexactly. The Angpow software aims at computing quickly and accurately the auto(z1 = z2) and cross (z1 = z2) angular power spectra between redshift bins andthe reciprocal angular correlation functions. The user has the possibility touse sparingly the Limbers approximation, to get better CPU performances withoutdegradation of the accuracy. The computation includes effects such as redshiftspace distortions (RSD) and magnification lensing. After a brief technicaldescription of the code, its validation and its performance for intensivecosmological parameter space explorations, I will show examples where oneclearly should not rely on Limber's approximation. Then I will illustrate theRSD and magnification lensing influences on the auto and cross angular powerspectrum shapes. This new software enables fast and accurate exploration of thecosmological parameter space especially in the context of wide photometricgalaxy surveys such as LSST and Euclid. |
| Databáze: | OpenAIRE |
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