AST 98-02980 Alex Szalay The structure of the universe beyond 100 Mpc The PI is addressing several major questions related to the large scale distribution of galaxies. The study of large scale structure of the Universe is one of the most dynamically evolving areas of astrophysics today. Various cosmologies provide estimates of the fluctuation spectrum (deviation from smoothness). This work by the PI helps to distinguish and constrain various cosmologies. In particular, the PI is measuring the fluctuation spectrum of the galaxy distribution on very large (> 100Mpc) scales, overlapping with measurements of the cosmic microwave background (CMB) fluctuations. This work will clarify the nature of the power spectrum on very large scales, lock the small and large scale normalization of the power spectrum together. The analysis techniques may result in major new developments in understanding the nature of the fluctuations on scales over 100 Mpc. The least know, and at the same time the most interesting part of the fluctuation spectrum is on scales between 100 - 300 Mpc, close to the horizon scale at equality and recombination, where we have the most reasons to believe that something may have left a detectable imprint, like the Doppler peaks in the CMB fluctuations. ***