Optimizing the Extraction of Cosmological Information from the Latest Spectroscopic Redshift Surveys

Session

III day

17 Jul 2025, 09:00

40. New frontiers for the 3PCF

Michele Ennio Maria Moresco (Istituto Nazionale di Astrofisica (INAF)), Michele Moresco (University of Bologna)

17/07/2025, 09:00

5. Field Level Inference with Fully Differentiable Hydrodynamical Physics

Benjamin Horowitz (Kavli IPMU)

17/07/2025, 09:30

Ongoing and upcoming spectroscopic redshift surveys will reach unprecedented depths and number densities, providing a wealth of information about galaxy clustering. However, current perturbative approaches struggle to accurately model small-scale clustering due to uncertainties in galaxy formation and bias modeling. While various astrophysical probes can inform these models, no existing...

11. Benchmarking field-level inference from galaxy surveys and its application to primordial non-Gaussianity analysis

Hugo Simon-Onfroy (CEA Paris-Saclay)

17/07/2025, 10:00

Field-level inference has emerged as a powerful framework to fully exploit cosmological information from next-generation galaxy surveys. It involves performing Bayesian inference to jointly estimate the cosmological parameters and initial conditions of the cosmic field directly from the observed galaxy density field. However, the computational feasibility of MCMC (Markov Chain Monte Carlo)...

41. Cosmology in the era of AI agents

Francisco Villaescusa Navarro

17/07/2025, 11:00

10. Going beyond the power spectrum: an analysis of BOSS & DESI galaxy clustering using the wavelet scattering transform.

Georgios Valogiannis (University of Chicago)

17/07/2025, 11:30

Optimal extraction of the non-Gaussian information encoded in the Large-Scale Structure (LSS) of the universe lies at the forefront of modern precision cosmology. In this talk, I plan to discuss recent efforts to achieve this task using the Wavelet Scattering Transform (WST), which subjects an input field to a layer of non-linear transformations that are sensitive to non-Gaussianity through a...

9. The clustering of dark matter haloes in alternative cosmological models

Massimiliano Romanello (Università di Bologna)

17/07/2025, 12:00

The clustering of large scale structure has been recognised as a fundamental cosmological probe, which offers us the possibility to constrain fundamental parameters, such as the matter density content of the Universe. Currently, the most acknowledged cosmological scenario is the $\Lambda$CDM model, which assumes that dark matter particles exist in a ‘cold' version, namely in the form of very...

24. Profile likelihoods for the neutrino mass, using latest cosmological datasets

Domitille Chebat (CEA Saclay - IRFU - DPhP)

17/07/2025, 12:30

We derive constraints on the neutrino mass using a frequentist approach based on likelihood profiles. Our analysis leverages the latest cosmological datasets, including DESI DR2 BAO and DR1 full-shape likelihoods, CMB and CMB lensing from Planck and ACT, recent Lyman-alpha 1D power spectrum emulation applied to eBOSS, and supernovae data.
Profile likelihoods offer several advantages when...

20. Perspective on simulations for future cosmological analysis

Dr Carmelita Carbone (INAF IASF-MI)

17/07/2025, 14:30

In this talk, we explore the trasformative role of cosmological N-body simulations in advancing our understanding of galaxy clustering. As galaxy surveys become increasingly detailed, the demand for accurate modelling intensifies. We delve into how deep learning acceleration and super resolution simulations offer unprecedented precision and minimize computational costs, paving the way for...

17. Cosmological probes with cosmic voids: advanced modelling and the latest results

András Kovács (Konkoly Observatory)

17/07/2025, 15:00

The ISW and gravitational lensing signals of cosmic large-scale structures probe the growth of structure in the low-redshift cosmic web. In this talk, I will summarise the recent results on detecting cosmic voids in the galaxy distribution, and their cross-correlations with CMB lensing and temperature maps, using different surveys such as DES, DESI, Euclid, Pan-STARRS, and also Gaia quasars. I...

19. Extracting cosmological information from the shape of cosmic voids

Giulia Degni (Università Roma Tre)

17/07/2025, 15:30

The emerging field of cosmic void studies provides a powerful probe for testing cosmological models and the properties of large-scale structure. Among the key statistics in this context is the void shape, which can be characterized by the void-galaxy cross-correlation function. This statistic encapsulates valuable information about the underlying cosmological model and the dynamics of the...

27. Unveiling Cosmic Voids Through Tracer Dynamics: A Novel Approach for Large-Scale Structure Analyses

Simone Sartori (CPPM/CNRS (Marseille))

17/07/2025, 16:30

With the rise of wide-area galaxy surveys, cosmic voids have emerged as powerful probes of the large-scale structure of the Universe, both as stand-alone observables and as complementary to galaxy clustering statistics. However, cosmological analyses of cosmic voids are subject to various observational systematics, exacerbated by their characteristic size and underdense environment.

To...

49. Panel discussion

17/07/2025, 17:00

3. Boosting HI-Galaxy Cross-Clustering Signal through Higher-Order Cross-Correlations

Eishica Chand (IISER PUNE)

After reionization, neutral hydrogen (HI) traces the large-scale structure (LSS) of the Universe, enabling HI intensity mapping (IM) to capture the LSS in 3D and constrain key cosmological parameters. We present a new framework utilizing higher-order cross-correlations to study HI clustering around galaxies, tested using real-space data from the IllustrisTNG300 simulation. This approach...

2. Cosmic Voids: Unlocking Novel Statistics Completing Galaxy Clustering

Giovanni Verza

In recent years, cosmic voids have emerged as powerful tools in cosmology, offering unique insights that complement traditional two-point statistics of galaxy clustering. To fully exploit the potential of voids for the vast datasets from ongoing and upcoming galaxy surveys, robust statistical modeling and careful data reduction are crucial.

This talk will delve into the application of the...

15. Cosmological constraints with Vornoi Volume Function

Ms Saee Dhawalikar (Inter University Centre for Astronomy and Astrophysics (IUCAA), Maharashtra India)

Voronoi Volume Function (VVF) is the distribution of cell volumes in the Voronoi tessellation of a given set of Comological tracers. It encodes information about the full clustering hierarchy of the tracer population and serves as an excellent higher-order statistic for probing non-Gaussianity in the large-scale structure. Despite its sensitivity to cosmological parameters, redshift-space...

14. Efficient simulation of galaxy lightcones and associated radiation fields

Andrei Albert Mesinger (Istituto Nazionale di Astrofisica (INAF))

I will present a substantial upgrade to the public simulation code, 21cmFASTv4, allowing efficient and flexible forward models of galaxy and IGM observables. In an end-to-end approach, we sample cosmological parameters, creating a 3D realization of the initial conditions. Dark matter halos are identified in Lagrangian space and then moved, together with the matter field, to Eularian space...

21. Field-level inference and the path towards percent-level constraint on growth of structure from spectroscopic surveys

Minh Nguyen (Kavli IPMU)

Field-level inference (FLI) is a framework to analyze galaxy clustering data from spectroscopic surveys directly at the level of the three-dimensional fields. This approach bypasses data compression, hence preserves the entire cosmological information encoded in the data. In this talk, I'll first present recent results from simulated data showcasing how FLI improves the constraint on growth of...