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Prochain séminaire le vendredi 17 janvier à 11h, salle de conférence de l’Observatoire.
Intervenant(e) : Sandrine Codis (IAP)
Titre : Alternative probes of cosmology using the large-scale structure of the Universe.
Résumé : In this talk, I will focus on two alternative probes of cosmology beyond two-pt correlation fonctions : topological invariants of the density field and count-in-cells statistics.
In a first part, I will show how to predict topological invariants for Gaussian fields in real space. Then, I will present recent results that allow to extend this theory to weakly non-Gaussian fields and to redshift space where some level of symmetry is broken. This formalism gives access to D(z) and to f=d log D/d log a- the linear growth rate of structures- which probe in particular the equation of state of dark energy and possible modifications of gravity.
In a second part, I will present some recent results in the field of count-in-cells statistics. The idea is to measure the mean densities within concentric spheres and study their joint statistics. Thanks to the spherical symmetry, one can do a mathematical conjecture that leads to surprisingly accurate predictions even in the mildly non-linear regime where standard PT calculations break down. This will be illustrated by comparisons with N-body results. Implications for Euclid will also be discussed.
Abonnez-vous au calendrier des séminaires : ICAL
Si vous souhaitez donner un séminaire, proposer un intervenant, ou obtenir d’autres renseignements, contactez Jérémy Blaizot (blaizot at obs.univ-lyon1.fr)
Les séminaires du CRAL ont généralement lieu le vendredi à 11 heures. Pour plus d’informations, veuiller contacter Jérémy Blaizot (blaizot at obs.univ-lyon1.fr).
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