New paper out! Cosmic shear with one component and its application to future radio surveys

We present a new approach to measuring cosmic shear: the one-component Kinematic Lensing (KL) method. This technique provides a simplified implementation of KL that reduces shape noise in weak lensing (WL) by combining kinematic information with imaging data, while requiring less observational effort than the full two-component KL. We perform simulated likelihood analyses to assess the performance of the one-component KL and demonstrate its applicability to future radio surveys. Our forecasts indicate that, for radio surveys, the one-component KL is not yet competitive with traditional WL due to the shallow redshift distribution of HI-selected galaxies. However, when applying this method to deeper spectroscopic surveys with stronger emission lines, the one-component KL approach could surpass WL in constraining power, offering a promising and efficient pathway for future shear analyses.

Figure: Left: Constraint on S8 when fixing the source redshift distribution to the KL (SNR ≥ 5) galaxy redshift distribution (the redshift histogram in the right panel of Fig. 2) for both WL (red) and one-component KL (blue). Right: Constraint on S8 when fixing the source number density to 0.856 arcmin−2 for both WL (red) and one-component KL (blue). Both scenarios are done by only sampling Ωm and σ8 to speed up the convergence.