Large-scale structure and microwave background anisotropies in cosmological models and stellar photometry techniques with the wide field/planetary camera of the Hubble space telescope

This dissertation consists of two separate parts. The first presents calculations of microwave background anisotropies at various angular scales and of expected large scale bulk velocities and mass correlation functions for a variety of models which include baryons, radiation, cold dark matter (CDM), and massive and massless neutrinos. Free parameters include {dollar}Omega{dollar}, {dollar}Hsb0{dollar}, the mass fractions of each component, and the initial conditions; nearly 100 different models are considered. Open and flat models with both adiabatic and isocurvature initial conditions are calculated for models without massive neutrinos. A set of flat models with both massive neutrinos and CDM with adiabatic initial conditions is also considered. Fitting functions for the mass transfer function and small angle radiation correlation function are provided for all of the models. A discussion of the evolution of the perturbations is presented. Results are compared with some recent observations of large scale velocities and limits on microwave background anisotropies. CDM and baryon models have difficulty satisfying observational limits, although they are not completely ruled out. Hybrid models with massive neutrinos and CDM satisfy current observational data.; The second part of the dissertation is a discussion of stellar photometry reduction techniques for data to be obtained with the Wide Field/ Planetary Camera (WF/PC) of the Hubble Space Telescope (HST). Detailed simulations are used to determine optimum techniques to use and to assess the expected accuracy of such techniques.