Constraining ??CDM with density-split clustering

The dependence of galaxy clustering on local density provides an effective method for extracting non-Gaussian information from surveys. two-point correlation function (2PCF) a complete statistical description Gaussian field. However, the late-time field becomes due to non-linear gravitational evolution and higher-order summary statistics are required capture all its cosmological information. Using Fisher formalism based halo catalogues Quijote simulations, we explore possibility retrieving this using density-split (DS) method, which combines regions different environmental density. We show that DS more precise constraints parameters $\nu \Lambda$CDM model compared 2PCF, provide suggestions where extra may come from. improves sum neutrino masses by factor $7$ factors 4, 3, 6, 5 $\Omega_{\rm m}$, b}$, $h$, $n_s$, $\sigma_8$, respectively. compare when environment is estimated real or redshift-space positions haloes. inclusion autocorrelation functions, in addition cross-correlation functions between environments haloes, recovers most lost estimate environment. discuss constructing simulation-based methods scenarios.