Stellar mass vs. velocity dispersion. The dotted line shows the local relation between bulge stellar mass and velocity dispersion, constructed by combining the ﹩M_{\mathrm{bulge}\,}﹩‐﹩M_{\mathrm{BH}\,}﹩ relation of Marconi & Hunt (2003) and the ﹩M_{\mathrm{BH}\,}﹩‐σ relation of Tremaine et al. (2002). Open squares and circles show the results of the simulations of Robertson et al. (2006), which tested the evolution of the M_BH‐σ relation with redshift. Typical uncertainties are shown by the error bars in the lower right corner.