Universe is flat, this is believed to be a consequence of inflation. In cosmology, inflation describes the theory that the universe underwent an exponential expansion of space the instant after the Big Bang. The expansion only lasted for 10−36 seconds after the Big Bang before the expansion slowed significantly. Experimental evidence from as early as the 1960s began to indicate that the density of the universe was very close to the critical density, or the density necessary for a flat universe.
