Speaker
Description
Generating a large set of HI intensity mapping simulations encompassing large cosmological volumes implies a prohibitive computational burden if one relies on traditional N-body-based methods. As such, a number of alternatives to overcome this issue have emerged over the years, from simple analytical prescriptions to more complex semi-empirical methods. In this talk, I will present an effort to produce such simulations in a fast but accurate way. These are obtained by combining dark matter fields in V=(10 Gpc/h)$^3$ volumes with smooth redshift evolution and full-sky lightcone geometry, generated with Augmented Lagrangian Perturbation Theory, with advanced field-level Eulerian bias prescriptions. In addition, these simulations are equipped with observational systematics mimicking SKA data. I will show that, in contrast to other simpler methods based e.g. on lognormal fields, our simulations include a high degree of nonlinearity and model correctly e.g. the BAO peak shift and broadening. Therefore, they represent an ideal tool to estimate covariance matrices and perform cosmological analysis such as BAO and full-shape analysis. Furthermore, I will discuss the prospect to generate the optical galaxy surveys simulations counterpart, to be able to perform cross-correlation studies with Euclid, DESI, and other state-of-the-art surveys.
| Topics | Cosmology |
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