Lectures on early universe models which can explain the currently observed structure on large scales. Survey of inflationary cosmology, the current paradigm for understanding the origin of the universe as we observe it today. Progress and problems in inflationary cosmology. Description of two alternative scenarios- the Matter Bounce and String Gas Cosmology. Lectures on basic concepts of the stellar atmospheres theory. Efficient numerical methods dealing with the stellar atmosphere problem, namely the method of complete linearization and Accelerated Lambda Iteration. The lectures summarize existing computer codes, with an emphasis on TLUSTY. Useful grids of model atmospheres and how the model atmospheres and synthetic spectra are used in quantitative stellar spectroscopy in order to determine basic stellar parameters and chemical abundances. Current state of knowledge of stellar- and intermediate-mass black holes is reviewed, particularly in regards to black hole populations in external galaxies. New modes of compact object accretion and potentially long-sought evidence for intermediate-mass black holes using high resolution X-ray telescopes.