Correlation Functions, Microwave Background, and Pancakes

The isothermal theories of galaxy formation encounter serious difficulties in accounting for the existence of large voids (see, e.g., Aarseth and Saslow 1982). The alternative picture of adiabatic fluctuations and pancake collapse (see, e.g., Doroshkevich et al. 1978 and references therein) faces difficulties due to: i) observed correlation functions, and ii) the absence of small-scale fluctuations in the microwave background