I have been looking online and in other resources for some answers to no avail. Thought I would sign up on astrophysics forums to find the answer.
What is the evidence and data for the period before the cosmic microwave background (CMB) in the early universe? In other words, is the idea of energy being in an infinitely dense point in the past simply just the most parsimonious explanation of winding back the clock from the expanding universe from 380,000 years to 0 (or Planck time)? Or is there observational and gathered data from the time prior to the CMB to validate that something was actually taking place prior to 380,000 years?
Has there been another model proposed that takes the CMB as the starting point instead? Or does the data nullify looking for another model apart from Big Bang and cosmic inflation?