# Was the Universe expanding before the beginning of inflation?

My point of view is that first there was the Big Bang singularity, and then the period of inflation which resulted in the observable Universe becoming many times bigger. But was the Universe expanding between the Big Bang singularity and the beginning of inflation?

• Are they even certain the Big Bang was a singularity? I think they're leaning towards an infinite universe now, enormous expansion, but not necessarily from a singularity. The Hubble expansion implied a singularity so it was believed for a while, but the infinite universe suggests not a singularity . . . er, I think. Not 100% sure though. :-) – userLTK May 21 '15 at 0:26
• The current theory of inflation has the universe at a radius of 15 Mpc after $10^{-34}$ sec. Does it really matter if the universe was slowly expanding after creation and before the inflation? How long could the period possible be if the inflation took most of the time? – LDC3 Jul 19 '15 at 21:59
• @LDC3 In what sense did the universe have a 15 MPc radius? The "visible universe" couldn't have been larger than light travel time distance, right? – LocalFluff Jul 20 '15 at 5:32
• @LocalFluff It's true that the "visible universe" is no larger than light travel time distance, but the universe can easily be larger than that. See pages.uoregon.edu/jimbrau/BrauImNew/Chap27/7th/… – LDC3 Jul 20 '15 at 6:02
• @LDC3 Unless universe is infinite, and there's no indication of it being curved. Space can expand anyway, but universe would never have a size. – LocalFluff Jul 20 '15 at 6:59