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...
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)...
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...
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...
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...
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...
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...
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...
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...
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...
