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Early Universe

Early Universe

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Early Universe

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  1. Early Universe Several diagrams showing the history of the Universe, emphasizing the earliest times matter  energy interchange; The first day The first 1000 Gyr; The first nanosecond;

  2. Early History of Matter • were p, n, e– made at some earlier time ? • if so, how ? • what about other particles (µ, υ, q… ) ? • what about anti-matter, was it also created ? • must consider energymatter interchange • must visit much earlier times • well-known physics: back to ~1µs • ~known physics : back to ~10-12 sec • ~rough guesses : back to ~10-35 sec • profound ignorance : before ~10-43 sec

  3. e–e+ e– p+ e– p+ Energy / Matter Interchange • Matter is very concentrated energy : E = mc2 • 1kg ≡ 1017 Joules = 100 megatons (big H bomb) • Examples of matter into energy: • In general: particle + anti-particle → energy • e– + e+ → 2γ (½ MeV photons created) • Examples of energy into matter: • In general: energy → particle + anti-particle • 2γ →p + p (need >1 GeV γs) • KE can also create matter: • (need KE > 2mec2 • = threshold energy) ¯

  4. pcle a-pcle photon Energy / Matter Interchange • Consider extremes of temperature: • temperature = KE / particle (Epcle = k×T) • what happens when Epcle > threshold energy ? • eg: 6×109K (electron); 1.1×1013K (proton) • matter/anti-matter created out of thermal energy • new matter arises in the midst of existing matter particles & antiparticles creation creation annihilation annihilation equilibrium energy photons (γ rays) thermal energy exchange

  5. The First Day ρN ρW ρA Temperature (K) 1014 1010 108 1012 QUARK HADRON LEPTON ERA RADIATION ERA q q 3q 2q e+,e−, γ γ dominates q q p,n,π…. free bound electron freezout proton freezout qq ↔ E pp ↔ E e+e−↔ E ¯ ¯ p, e− 1:1 p, He4 12:1 (3:1) p, γ 1:109 ν decouple 2p2n→ He4 H fusion Matter: 109 + 1 (p) Anti-matter: 109 (p) p, n : 1 e±, γ : 109 ¯ e+e−→ 2γ pp →2γ ¯ (e±,μ±,γ….) p:n → 1:1 7:1 10-8 10-6 10-4 10-2 1 102 104 Time (s) μs ms min hr day Expansion & Cooling

  6. p+e−→ H atoms free → bound ionized opaque neutral transparent matter free to collapse Sound waves : begin → grow The First 1000 Gyr The First Day QUARK HADRON LEPTON ERA RADIATION ERA 10-8 10-6 10-4 10-2 1 102 104 Time (s) Temperature (K) 10 105 104 103 102 1 106 RADIATION ERA MATTER ERA DARK ENERGY ERA ργ > ρM ργ = ρM ρM = ρDE ρM> ργ ρDE > ρM re-ionized accelerating expansion, very empty stars p+,e−, He4, DM (trace) photons dominate present QSOs X UVBGYOR galaxies H exhausted stars die 1 102 104 106 108 1010 1012 kyr Time (yr) Gyr Now

  7. Strong Strong Strong Electro- magnetic GUT Electro- Weak Electro- Weak Weak Gravity Gravity Gravity Gravity The First Nanosecond ~1028K ~1028 ~1027K ~1015K GUT ERA QUARK ERA R × 1060 q (109+1) ¯ X X q (109) ¯ ? ? Seed fluctuations INFLATION reheat ~10-36 ~10-34 ~10-32 10-12 10-10 Time (s) The First Day QUARK HADRON LEPTON ERA RADIATION ERA 10-8 10-6 10-4 10-2 1 102 104 Time (s) The First 1000 Gyr DARK ENERGY ERA RADIATION ERA MATTER ERA 1 102 104 106 108 1010 1012 Time (yr)