Grâce aux mesures de lentillage gravitationnel et de clustering des galaxies, Euclid posera des contraintes sans précédent sur l'Univers récent. D'autre part, des observations CMB de haute qualité (Planck et futures expériences) sont capables d'imposer des contraintes strictes sur l'Univers primordial. La combinaison de ces deux sources d'informations cosmologiques peut constituer un bras de...
Constraining the mass-observable relations is a key ingredient for cluster cosmology. In particular, for optical surveys such as the Rubin LSST, the cluster abundance relies on the determination of the mass-richness relation. In that context, weak gravitational lensing by galaxy clusters can be used as a powerful tool to estimate cluster masses. We use the cluster-galaxy weak lensing in the...
We study Bianchi cosmologies coupled to a matter source that has the field theoretical description of a solid. Models
of solid inflation are known for not being very efficient in diluting away anisotropy. While confirming this fact, our study finds another potential feature of Solid inflation, namely a ``rotation” of the principal axes of the expansion.
Such a rotation is not just a ...
Quantum gravitational effects are usually associated with the Planck scale but they could also become important at low energy if the wavefunction of the metric field fails to be peaked around a classical configuration.
I try to understand such deviations from classicality within canonical quantum gravity by introducing a "fluid of observers" in the low energy theory and defining a distance...
The Fermilab measurement of the anomalous magnetic moment of muons seems to be at odds with the standard model of particle physics. Coupled scalar fields such as the chameleon or the symmetron, which modify gravity locally, could account for the discrepancy.
Constraints on the cosmological concordance model parameters are usually obtained using the locally measured value of the gravitational constant G. Here we relax this assumption and determine the impact of such hypothesis on the physics involved in the prediction of the cosmological observables. Using the latest CMB temperature and polarization correlations data and distance measurements from...
In this talk I will discuss about the impact of magnification bias on the determination of the growth rate from redshift-space clustering. We use a the RayGal suite of $N$-body simulations that accounts for the fully non-linear structure formation and perform realistic galaxy clustering analyses, similarly as in observations, in different regime of magnification bias. We investigate a minimal...
I will present constraints on the tensor-to-scalar ratio r using Planck data as described in [Tristram et al., A&A, 647, A128 (2021)].
In this paper, we use the latest release of Planck maps (PR4), processed with the NPIPE code, which produces calibrated frequency maps in temperature and polarisation for all Planck channels from 30 GHz to 857 GHz using the same pipeline. We computed...
We study the inflationary consequences of Degenerate Higher Order Scalar Tensor (DHOST) theories in a de Sitter background. We perturb the de Sitter background by operators breaking either the degeneracy condition, i.e scordatura DHOST, or the shift symmetry in the scalar field. We first consider derivative scordatura and find that in all cases the power spectra of curvature perturbations are...
