The abundance of galaxy clusters is a sensitive probe to the amplitude of matter density fluctuations, the total amount of matter in the Universe as well as its expansion history. Inferring correct values and accurate uncertainties of cosmological parameters requires accurate knowledge of cluster abundance statistics, encoded in the likelihood function. We present a framework to test the...
"The question of dark energy has been revived in the recent years in string phenomenology, in part due to so-called swampland conjectures. Getting well-controlled string effective theories with de Sitter spacetimes is very challenging, asking the question of alternatives to reproduce observed cosmology (quintessence, multifield inflation, or else).
Class_sz (Bolliet et al) is a code built on Class (Lesgourgues et al) which enables to compute nearly all cosmological power spectra relevant to upcoming CMB and LSS surveys (tsz and ksz, lensing, galaxies, CIB), including cross-correlations and cluster counts for SZ surveys. It is being used in the developpement of pipelines within the Atacama Cosmology Telescope and Simons Observatory. I...
We consider coupled dark energy (CDE) cosmologies, where dark matter particles feel a force stronger than gravity, due to the fifth force mediated by a scalar field which plays the role of dark energy. We perform for the first time a tomographic analysis of coupled dark energy, where the coupling strength is parametrised and constrained in different redshift bins. This allows us to verify...
Abstract: One of the most striking predictions of the standard model of cosmology is to trace back the origin of all the structures of our universe to quantum fluctuations. If we want to access the full implications of this statement, we need to evaluate the quantum information properties of inflationary models. In this talk, I will present the Cosmological Open Quantum System program and...
In order to probe modifications of gravity at cosmological scales one needs accurate theoretical predictions. N-body simulations are required to explore the non-linear regime of structure formation but they are, however, very time consuming. In this work we build an emulator that performs an accurate and fast interpolation between the predictions of a given set of cosmological simulations in...
"Future Large Scale Structure surveys are expected to improve over current bounds on primordial non-Gaussianity (PNG), with a significant impact on our understanding of early Universe physics. However, the level of such improvements strongly depends on the extent to which late time non-linearities erase the PNG signal on small scales.
In this talk, I will present our results based on the...
In this talk, I will present the paradigm of the effective field theory of large-scale structures (EFTofLSS) and how it can be used to constrain cosmological models. First I will discuss the consistency of this theory and its predictive power within the LCDM model, and then I will present the constraints of the EFTofLSS applied to BOSS and eBOSS data on some alternative cosmological models.
This talk will provide an overview of the status and plan of
the LSST Observing Strategy. A particular emphasis will be placed on the
impact of the LSST survey on cosmology with Type Ia Supernovae (SNe Ia).
It will be shown that having a deep survey is critical to measure
cosmological parameters with high accuracy.
"The concordance model in cosmology, ΛCDM, performs extremely well in accounting for most current cosmological observations with high accuracy.
However, the model faces several tensions with recent cosmological data and their increased accuracy. The discrepancy between the values of the Hubble constant H0 obtained from direct distance scale measurements and the cosmic microwave background...
"The gas mass fraction in galaxy clusters is a convenient probe to use in cosmological studies, as it can help derive constraints on a collection of cosmological parameters. It is however subject to various effects from the baryonic physics inside galaxy clusters, which may bias the obtained cosmological constraints. Among different aspects of the baryonic physics, in this presentation I focus...
The Cosmic Microwave data at very small scales are known to probe not only primordial CMB fluctuations but also many extragalactic components such as tSZ, kSZ, CIB, points sources.
I will show how to use the cosmological dependent SZ signatures (tSZ and kSZ) at small scales coherently with the large scales and the cosmology framework in Planck and SPT experiments to retrieve both...
