  We explore the information content of 21cm intensity maps in redshift space
using the 1-loop Effective Field Theory power spectrum model and the bispectrum
at tree level. The 21cm signal contains signatures of dark matter, dark energy
and the growth of large-scale structure in the Universe. These signatures are
typically analyzed via the 2-point correlation function or power spectrum.
However, adding the information from the 3-point correlation function or
bispectrum will be crucial to exploiting next-generation intensity mapping
experiments. The bispectrum could offer a unique opportunity to break key
parameter degeneracies that hinder the measurement of cosmological parameters
and improve on the precision. We use a Fisher forecast analysis to estimate the
constraining power of the HIRAX survey on cosmological parameters, dark energy
and modified gravity.
