BE-HaPPY: bias emulator for halo power spectrum including massive neutrinos

We study the clustering properties of dark matter haloes in real- and redshift-space in cosmologies with massless and massive neutrinos through a large set of state-of-the-art N-body simulations. We provide quick and easy-to-use prescriptions for the halo bias on linear and mildly non-linear scales, both in real and redshift-space, which are valid also for massive neutrinos cosmologies. Finally we present a halo bias emulator, BE-HaPPY, calibrated on the N-body simulations, which is fast enough to be used in the standard Markov Chain Monte Carlo approach to cosmological inference. For a fiducial standard Lambda CDM cosmology BE-HaPPY reproduces the simulation inputs with percent or sub-percent accuracy for the halo mass cuts it is calibrated on (M > {5 x 10(11); 10(12); 3 x 10(12); 10(13)}h(-1) M-circle dot) on the scales of interest (linear and well into the mildly non-linear regime). The approach presented here represents a well defined route to meeting the halo-bias accuracy requirements for the analysis of next-generation large-scale structure surveys. The software BE-HaPPY can run both in emulator mode and in calibration mode, on user-supplied simulations outputs, and is made publicly available.