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Galaxies are the basic structural element of the universe; galaxy formation theory seeks to explain how these structures came to be. I trace some of the foundational ideas in galaxy formation, with emphasis on the need for non-baryonic cold dark matter. Many elements of early theory did not survive contact with observations of low surface brightness galaxies, leading to the need for auxiliary hypotheses like feedback. The failure points often trace to the surprising predictive successes of an alternative to dark matter, the Modified Newtonian Dynamics (MOND). While dark matter models are flexible in accommodating observations, they do not provide the predictive capacity of MOND. If the universe is made of cold dark matter, why does MOND get any predictions right?
Searches for dark matter annihilation signals have been carried out in a number of target regions such as the Galactic Center and Milky Way dwarf spheroidal galaxies (dSphs), among a few others. Here we propose low surface brightness galaxies (LSBGs)
We investigate in detail the hypothesis that low surface brightness galaxies (LSB) differ from ordinary galaxies simply because they form in halos with large spin parameters. We compute star formation rates using the Schmidt law, assuming the same ga
Recent advancements in the imaging of low-surface-brightness objects revealed numerous ultra-diffuse galaxies in the local Universe. These peculiar objects are unusually extended and faint: their effective radii are comparable to the Milky Way, but t
Our statistical understanding of galaxy evolution is fundamentally driven by objects that lie above the surface-brightness limits of current wide-area surveys (mu ~ 23 mag arcsec^-2). While both theory and small, deep surveys have hinted at a rich po
The observed rotation curves of low surface brightness (LSB) galaxies play an essential role in studying dark matter, and indicate that there exists a central constant density dark matter core. However, the cosmological N-body simulations of cold dar