The fifth (and final) data release of the Kilo-Degree Survey (KiDS) provides significantly more than just an increase in survey area. Instead, additional observations couple with improvements in data quality, data reduction, and value-added data-products, to make KiDS-DR5 the most robust and reliable release produced by KiDS to date. We leverage the lensing sample from this state-of-the-art...
We present a unified assessment of Bayesian model comparisons and cross-dataset tensions for the (still) standard $\Lambda$CDM model and some minimal extensions (curvature $\Omega_K$, sum of neutrino masses $\sum{m_\nu}$, dynamic dark energy $w$, or $w_0$ and $w_a$) in light of data from the cosmic microwave background (CMB), baryon acoustic oscillations (BAO), and supernovae (SN). Our...
We present a coherent cosmological analysis that combines data from the Planck satellite, the Atacama Cosmology Telescope (ACT), and the South Pole Telescope (SPT). We construct a unified likelihood that jointly fits temperature and polarization power spectra from all three datasets, implementing consistent modeling of Galactic and extragalactic foregrounds as well as instrumental systematics....
Measurements of spectral distortions of the CMB are one of the pillars on which we built our standard cosmological model. While measurements of CMB anisotropies have massively improved since their discovery, CMB spectral distortion were last measured by the COBE/FIRAS mission in the 1990s over the full sky. I will show how a re-analysis of archival data of COBE/FIRAS using modern foreground...
SMICA (Spectral Matching Independent Component Analysis) is a non-parametric method (Delabrouille et al. 2003; Cardoso et al. 2008) that operates in the spherical harmonic domain. It relies on the assumptions of statistical isotropy and Gaussianity of the signals. In this work, we relax the Gaussianity assumption to allow for weak non-Gaussianity, including three-point correlation functions of...
Claims have appeared in the literature of a statistically significant signal of parity violation in higher-order correlation functions from galaxy surveys. I will present some estimators of parity violation for the CMB bispectrum.
Context
Galaxy clusters in formation, or protoclusters, are important sites regarding the star formation history and the evolution of large scale structures, but only their galaxy members have been observed so far. The majority of their mass is expected to be under the form of non baryonic dark matter and intergalactic cold gas.
Aims
The Planck high redshift...
The second Planck catalogue of Sunyaev-Zeldovich sources (PSZ2) was originally presented by the Planck Collaboration as part of their 2015 data release. Along with the catalogue, a cosmological analysis was also published, conducted on the PSZ2 cosmological sample that contains 439 high signal-to-noise cluster candidates. However, this analysis was limited by the precision of its mass...
High-precision observations of the Cosmic Microwave Background (CMB) will yield improved measurements of the kinetic Sunyaev–Zel’dovich (kSZ) effect. In order to investigate the sensitivity of the kSZ signal to astrophysics, we build a neural-network emulator of the kSZ power spectrum, trained on the LoReLi II reionisation simulations, to enable fast inference of galaxy properties during...
Gravitational lensing of the Cosmic Microwave Background (CMB) is becoming one of our sharpest cosmological probes, with surveys such as SPT-3G and the Simons Observatory delivering deep polarization maps. In this talk, I will present a new optimal estimator for CMB lensing, which outperforms the widely used quadratic estimator in both accuracy and robustness. I will highlight recent advances...
The tightest constraints on the tensor-to-scalar ratio (BK18) are strongly limited by gravitational lensing, which can be reduced by high-resolution SPT-3G observations. SPT-3G and BICEP (SPO) have collected now enough data to achieve, in principle, 3 times better constraints on r than currently published (sigma(r) \sim 0.003 vs 0.009 now)), thanks to de-lensing. I'll discuss initial lensing...
Combining CMB and large-scale structure (LSS) data allows us to probe cosmic evolution from recombination to the present, constraining the amounts of baryonic and dark matter and testing general relativity on cosmological scales, as well as shedding light on the nature of dark energy.
In this talk, I present preliminary results from the clustering analysis of a magnitude-limited galaxy sample...
The Simons Observatory (SO) is already taking data and moving toward full science operations with its suite of small- and large-aperture telescopes. In this talk I will present recent updates on the project and outline its scientific potential, based on new forecasts.
The Simons Observatory (SO) is an ensemble of telescopes located in the Atacama Desert in Chile, targeting the detection of primordial B-modes in the polarization of the cosmic microwave background (CMB). The Small Aperture Telescopes (SATs) have been taking data for over a year and have already delivered their first CMB maps, which are currently under analysis. In this talk, we will present...
We investigate the impact of non-ideal half-wave plates (HWPs) on CMB polarization measurements in experiments such as the Simons Observatory and LiteBIRD. Because both foreground emission and instrumental effects vary with frequency, they are closely intertwined, and addressing one without the other can interfere with our estimation of cosmological parameters.
Through end-to-end...
Planck-HFI highly sensitive bolometers were considerably affected by cosmic-rays, producing spurious signals appearing as glitches in the raw astrophysical data. Since, the effect of cosmic rays on detectors is a major concern for future similar space missions. Their instruments will have a larger detection surface, an increased sensitivity, and much more stringent requirements on the...
Measuring r in low SNR, foreground-dominated observations of CMB B-modes is prone to biases that are hard to avoid and estimate when the exact properties of foreground emission are not known a priori. We use SMICA to forecast constraints on r for future ground-based observations and obtain unbiased constraints for various levels of foreground complexity.
The LiteBIRD satellite mission, an international collaboration led by the Japanese space agency (JAXA), aims to measure the CMB B-mode polarization with high precision, utilizing high-sensitivity instruments and large sky coverage to constrain the tensor-to-scalar ratio with unprecedented precision. The main difficulty in measuring this component lies first in its extremely small amplitude,...
Accurate statistical characterization of Galactic foregrounds is crucial for extracting cosmological information from CMB polarization data. However, the complexity of the interstellar medium leads to non-Gaussian structures that cannot be fully captured by traditional summary statistics, like the power spectrum. On the other hand, simulation and machine-learning approaches, while informative,...
