Dirac Talks: Einstein's Equations, Curvature, and the Hilbert Action - II

I will continue with a short recap of parallel transport and
Riemann curvature. From here I will finally introduce the stress-energy
tensor and the notion of energy-momentum conservation. We will then
derive the Einstein equation from the Hilbert Action, and discuss the
fact that the Hilbert Action is the most general action of its type. We
will then be able to discuss the various ways that the action may be
modified in order to attain alternative theories of Gravity. Then, given
time, we will discuss a particular case of such modification, often
referred to as the "Wave Dark Matter" or "Fuzzy Dark Matter" theory.