Leonard Susskind discusses the inhomogeneities in the cosmic microwave background, and derives the current theory whereby these inhomogeneities are created by quantum fluctuations in the inflaton field of the early universe. These fluctuations lead to variations in energy density that ultimately result in the formation of galaxies. (March 18, 2013)

Leonard Susskind presents the theory of cosmological inflation under which the early universe expanded exponentially before the Big Bang. This theory explains the lack of observed magnetic monopoles and the uniformity of the cosmic microwave background radiation. (March 11, 2013)

Leonard Susskind examines one of the fundamental questions in cosmology: why are there more protons than anti-protons in the universe today? The answer lies in theory of baryogenesis in the very early universe. (March 4, 2013)

Leonard Susskind examines the temperature history of our universe. The universe switched from radiation-dominated to matter-dominated when it was about one million times hotter than it is today, and the matter and energy decoupled from each other and the universe became transparent when it was about one thousand times hotter that it is today. (February 25, 2013)

Leonard Susskind develops the energy density allocation equation, and describes the historical progress of the solution to this equation. He then describes the observations of luminosity and red-shift that have led to the correct solution for today's universe - which is dominated by dark energy.

After reviewing the cosmological equations of state, Leonard Susskind introduces the concept of vacuum energy. Vacuum energy is represented by the cosmological constant, and is also known as dark energy. (February 11, 2013)

Leonard Susskind introduces the Einstein field equations of general relativity and thermodynamic equations of state to the analysis of the expanding universe. (February 4, 2013)

Leonard Susskind presents three possible geometries of homogeneous space: flat, spherical, and hyperbolic, and develops the metric for these spatial geometries in spherical coordinates. (January 28, 2013)

Leonard Susskind solves the expansion equation for universes with zero total energy, and then adds a non-zero total energy term, which leads to an exploration of matter versus radiation dominated universes. (January 21, 2013)

Leonard Susskind introduces the study of Cosmology and derives the classical physics formulas that describe our expanding universe. (January 14, 2013)