Imprints of Galaxy Clsutering Evolution on Delta T / T
  The nonlinear evolution of matter clustering induces temperature anisotropies in the cosmic microwave background. The fluctuations in temperature are produced at a relatively low redshift, $z\simlt 10$, and consequently are not affected by the uncertain reionization proccesses that occurred at earlier epochs. The amplitude of the effect depends on the evolution model assumed for galaxy clustering. For plausible parameter choices, the temperature fluctuations are in the range $10^{-6}\simlt \Delta T/T \simlt 10^{-5}.$ Observed limits on $\Delta T/T $ would be violated if nonlinear clustering on present cluster scales commenced prior to $z\sim 10.$ 
Enrique Martinez- Gonzalez, Jose L. Sanz, Joseph Silk