Radial velocity vs. radial position of particles (or shells) in dark matter halos. The solid lines are solutions of eq. (5) for a range of halo inner slope values α. The points connected by a dashed line are the predictions of an analytic model: the points satisfy both eq. (5) and the condition ﹩v_{\mathrm{rad}\,}\propto r^{\alpha -2}﹩; see § 5.1 for details. Horizontal arrows represent data taken from our dark matter halos; the cross symbol at (−0.70, 0.05) represents the high‐resolution N‐body halo of Ghigna et al. (1998); see § 5.2 for more details.