-
Angus Wright (Ruhr University Bochum)13/10/2025 16:30
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...
Go to contribution page -
Etienne Burtin (IRFU/CEA - Université Paris-Saclay)13/10/2025 16:50
-
Dr Lukas Hergt (IJCLab, IN2P3, CNRS)13/10/2025 17:10
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...
Go to contribution page -
Matthieu Tristram (IJCLab, CNRS)13/10/2025 17:30
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....
Go to contribution page -
Giulio Fabbian (Institut d'Astrophysique Spatiale (IAS))13/10/2025 17:50
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...
Go to contribution page -
Michele Citran (APC, IJCLab)13/10/2025 18:10
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...
Go to contribution page -
Dr Martin Bucher (APC)13/10/2025 18:30
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.
Go to contribution page -
Tanguy DUSSERRE (Institut d'Astrophysique Spatiale)14/10/2025 09:00
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
Go to contribution page
The Planck high redshift... -
Gaspard Aymerich (Institut d'Astrophysique Spatiale, Université Paris-Saclay)14/10/2025 09:20
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...
Go to contribution page -
Dr Lisa Mc Bride (Institut d'Astrophysique Spatiale)14/10/2025 09:40
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...
Go to contribution page -
Ola Kusiak (Cambridge)14/10/2025 10:00
In this talk, I will present the projected-fields kSZ estimator, where the kSZ signal is squared before cross-correlating it with a LSS field to avoid the cancellation of the signal due to electron velocity, which is equally likely to be positive or negative. Crucially, this estimator does not require spectroscopic redshift information.
Go to contribution page
I will discuss new developments on the projected-fields... -
ll783 Legrand (DAMTP, University of Cambridge)14/10/2025 10:50
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...
Go to contribution page -
Julien Carron (University of Geneva)14/10/2025 11:10
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...
Go to contribution page -
Dr Margherita Lembo (Institut d'Astrophysique de Paris (IAP))14/10/2025 11:30
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.
Go to contribution page
In this talk, I present preliminary results from the clustering analysis of a magnitude-limited galaxy sample... -
M. Thibaut Louis (LAL)14/10/2025 11:50
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.
Go to contribution page -
Amalia Villarrubia Aguilar (APC), Pierre Masson (APC)14/10/2025 12:10
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...
Go to contribution page -
Ema TSANG KING SANG (APC-CNRS)15/10/2025 09:00
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...
Go to contribution page -
Anaïs Besnard (Institut d'Astrophysique Spatiale (IAS))15/10/2025 09:20
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...
Go to contribution page -
Mathias Regnier (IRAP)15/10/2025 09:40
We present the development of a local bubble model designed to characterize polarized Galactic foregrounds emission at high Galactic latitudes. The framework focuses on modeling the polarized dust emission (Stokes Q and U) as well as the synchrotron contribution, under the hypothesis of a magnetized local cavity surrounding the Solar neighborhood. By combining observational constraints with...
Go to contribution page -
Jacques Delabrouille (IN2P3)15/10/2025 10:00
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.
Go to contribution page -
Hoang Viet Tran (APC, Université Paris Cité)15/10/2025 10:20
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,...
Go to contribution page -
Pierre CHANIAL (APC)15/10/2025 11:00
We present Furax, a Python library for solving inverse problems in astrophysical and cosmological data analysis, with focus on CMB observations.
Why JAX? JAX provides JIT compilation, automatic differentiation, and seamless GPU/TPU parallelization essential for large-scale matrix operations in CMB analysis. Its functional programming paradigm enables efficient, composable linear...
Go to contribution page -
Wuhyun Sohn (APC / CNRS)15/10/2025 11:20
I will present three applications of FURAX, a JAX-powered, open-source framework designed for modular and efficient CMB data analysis. First, I will discuss mapmaking—the conversion of time-ordered data into sky maps—with an emphasis on strategies to mitigate systematic effects. Second, I will show how FURAX enables robust component separation in the map domain, extracting CMB signals from sky...
Go to contribution page -
Artem BASYROV (APC, CNRS)15/10/2025 11:40
Traditionally beams are treated in the harmonic space. However, it imposes several disadvantages like inability to treat non-spherical beams, always requiring an approximation. In the context of Simons Observatory experiment, we demonstrate a different approach based on treating the beams on a map-level. Accelerated by JAX and powered by FURAX software, it allows to circumvent the limitations...
Go to contribution page -
Simon Biquard (APC / CNRS)15/10/2025 12:00
Based on https://arxiv.org/abs/2509.16302
Go to contribution page -
Dr Alexandros Tsouros (LPENS Paris)15/10/2025 12:20
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,...
Go to contribution page -
Sébastien Pierre (LPENS)15/10/2025 12:40
Extracting a signal of interest (LSS, CMB, Galactic emission…) from contaminated observations is a central challenge in many astrophysical and cosmological analysis. However, instrumental systematics, Galactic foregrounds or other contaminants usually makes the forward process stochastic and non-invertible, leaving the inverse problem ill-posed. A probabilistic framework is therefore required...
Go to contribution page -
Marian Douspis (IAS)
Planck has been producing the first tSZ power spectrum estimate from "all-sky" y-map in 2013. New estimates has been produced from updates of the ymap in parallele to estimation derived from the CMB data analyses by Planck, ACT and SPT. The latter just released there last results in the last month. I will review the different (sometimes in tension) signal estimates (and analyses they are...
Go to contribution page
Choisissez le fuseau horaire
Le fuseau horaire de votre profil: