Refining the Big Bang
• Flatness Problem – why so close to a critical universe?
• Horizon Problem – why is background all same T?
• SOLVED BY AN “INFLATIONARY UNIVERSE”
– “Grand Unified Theories” of combined
Gravity/Weak/Electric/Nuclear forces predict very rapid
expansion at very early time:  “inflation”
– When inflation ends, all matter moving away with v=vescape
(flat universe – curvature forced to zero)
– Also solves horizon problem – everything was in causal contact