From Planck time to the CMB would certainly be cosmology, and it would take a great deal from high energy physics, the Standard Model, supersymmetry, LQG, superstring theory, SMT (what DOES it stand for?), and so on. If you're seaching for answers about what happened in the first 10-43
seconds (or what happens at 'temperatures' greater than 1030+
K), I leave it to the PF old-timers, especially marcus and selfAdjoint, to suggest how best to proceed.