How do galaxies assemble their stellar mass across cosmic time? Despite a well formulated, 35 year-old framework of hierarchical, galaxy formation in a Universe dominated by dark matter and dark energy, this basic question, which is central to the study of galaxy evolution, still begs for a satisfactory answer. In this talk I present a novel method to study galaxy formation, which is both simple and transparent. Unlike semi-analytical models and hydrodynamical simulations, this model can easily fit all existing data, providing valuable insights into the physics that regulate the assembly of galaxies across cosmic how. In particular, I present evidence for a new, characteristic scale in galaxy formation, which regulates the formation of dwarf galaxies, and which may be crucial for understanding reionization.
Followed by wine and cheese in Pupin 1402.