1. Inflation and the origin of structures Richard Lieu OB-201F

2. Inflation

5. Albert Einstein

18. Cosmological redshift

19. What does the Hubble expansion mean? • We are not at the center of the universe, nor is everything `running away’ from us (Copernican worldview). • Expansion of the universe has no center.

22. What else does the Hubble expansion mean? • Expansion also means density and temperature were higher in the past (fireball).

23. What else does the Hubble expansion mean? • Expansion also means density and temperature were higher in the past (fireball). • There was a time when all the space we can imagine around us was crunched to a point – the moment of the Big Bang.

24. What else does the Hubble expansion mean? • Expansion also means density and temperature were higher in the past (fireball). • There was a time when all the space we can imagine around us was crunched to a point – the moment of the Big Bang. • Thus, expansion means there was a special, or privileged, time (Copernicus!).

25. What else does the Hubble expansion mean? • Expansion also means density and temperature were higher in the past (fireball). • There was a time when all the space we can imagine around us was crunched to a point – the moment of the Big Bang. • Thus, expansion means there was a special, or privileged, time (Copernicus!). • The universe has a finite lifetime.

27. Alternative Principles of Cosmology The universe looks the same: • Copernican anywhere • Perfect anywhere and anytime • Anthropic anywhere and at a privileged time

30. Einstein abandons Lambda Much later, when I was discussing cosmological problems with Einstein, he remarked that the introduction of the cosmological term was the biggest blunder of his life.  -- George Gamow, My World Line, 1970

32. Willem de Sitter

34. Alexander Friedman The universe can expand (but in a decelerated manner) if it started in a Big Bang.

38. Riddles from the universe • What is Lambda (or `dark energy’)?

40. We can detect these very cool photons in every direction: Critical prediction of Big Bang theory! back in time 1100

41. Photons rarely interact with matter again • At redshift ≈1100, have a thermal spectrum of 3000K • As the Universe expands photons shift to longer wavelengths, making a cooler spectrum across Universe

43. Future Clusters II. What caused hot & cold spots in the Cosmic Microwave Background? • Slightly higher density regions pulled matter towards or away from us. • Slight motions at z=1100 caused some regions to be slightly Doppler redshifted or blueshifted

44. WMAP map of the “edge of the observable universe” plotted as a sphere

45. Riddles from the universe • What is Lambda (or `dark energy’)?

46. Riddles from the universe • What is Lambda (or `dark energy’)? • What is the origin of density seeds?

48. Flat +ve curvature -ve curvature

49. Riddles from the universe • What is Lambda (or `dark energy’)? • What is the origin of density seeds?

50. Riddles from the universe • What is Lambda (or `dark energy’)? • What is the origin of density seeds? • Why is space Euclidean (or flat)?