Tomographic Cosmic Shear and the Growth Index: Bin-by-Bin Amplitudes in Five Source Bins

Dividing a shear source sample into five photometric-redshift bins between redshift 0.1 and 1.2, this paper computes the convergence power at multipole 300 for each bin, obtaining 1.053e-11 for the lowest bin and 7.942e-10 for the highest, and a relative per-bin amplitude, defined against the full-sample power, which rises from 0.112 in the lowest bin to 0.970 in the highest. The linear growth factor at the middle of the range, redshift 0.6, is 0.733. A change of the growth index from 0.55 to 0.65 alters the growth factor at that redshift, and hence the shear amplitude fed by it, by -5.50 percent. Tomographic data of current quality, with per-bin amplitude uncertainties of several percent, can therefore register growth-index changes of this size only marginally, and cannot separate them from per-bin redshift or calibration errors of the same size. The bin-by-bin numbers are computed from stated assumptions, not measured.