I just finished Leonard Susskind's video course on cosmology. A question never raised nor mentioned in the course was conservation of information. I mean information in the sense of Liouville's theorem/Unitary operators in QM/Event horizon paradoxes ... At one point Susskind said that the quantity of information and the number of photons in the universe are roughly the same thing. But I did not hear him say that the number of photons+particles was anywhere near constant during inflation and the big bang. My question: Should we believe that information was conserved during the big bang and the inflationary period?