Speaker
Description
We present a joint analysis of galaxy clustering and galaxy-galaxy lensing measurements from BOSS galaxies using the method of simulation-based emulation combined with halo occupation distribution model. Our emulator is constructed with Aemulus $\nu$ simulations, a suite of $w\nu$CDM N-body simulations with massive neutrinos as an independent particle species. We combine the small-scale analysis of galaxy clustering from $0.1h^{-1}$Mpc to $60~h^{-1}$Mpc and galaxy-galaxy lensing from $1.7h^{-1}$Mpc to $60~h^{-1}$Mpc to perform cosmological constraint. We split the BOSS galaxies into three redshift bins to measure their clustering and employ galaxies from Dark Energy Camera Legacy Survey and Hyper Suprime-Cam as source galaxies to measure galaxy-galaxy lensing separately. We find that the addition of galaxy-galaxy lensing will significantly improve constraint power on $S_{8}=\sigma_8(\Omega_m/0.3)^{0.5}$, with weak improvement on the constraint of $f\sigma_{8}$ . Our results of $f\sigma_{8}$ indicate tensions of around $2 \sim 4\sigma$ below the results of CMB observations from Planck. For $S_{8}$, our results from different observational data are also lower than the Planck result, which can be mitigated but not resolved when considering possible systematics in lensing measurement. These tensions with CMB observations in our work are consistent with some recent works of large-scale structure analysis, including measurements of galaxy clustering, galaxy-galaxy lensing, cosmic shear but not all of them. As a byproduct, our analysis also provides a preference of non-zero neutrino mass but without strong enough significance, with the constraining power dominated by the clustering measurement at intermediate to small scales. Given the accuracy of our model and the observational data, it is anticipated that more and better spectroscopic data is able to shed light on the constraints on this fundamental property in the near future.
