Histoire de l’univers infinite, finite, infinite,

 c

Early universe: photons + ultra-relativistic particles radiation era

Grand and super unification of all interactions

Thermal equilibrium: interaction rate> volume expansion interaction rate per unit time (one particle): (n=density) volume expansion: relative expansion per unit time: relativistic particles loose energy between interactions because of expansion

if as soon as

When kt<2m  c 2 = 280 MeV, t=10 -4 s, the last hadrons annihilate, except for a few non relativistic protons and neutrons, surviving thanks to a small asymmetry between matter and antimatter ( ). This is today’s matter! This requires 1)small B non conservation, not included in the SM GUT 2)CP non conservation CKM q mixing contributes, but may not be sufficient neutrino mixing matrix also has a CP non conservation phase, which may do the job 3) Non equilibrium

t<1 s: Neutrino freeze out at kT=0.8 MeV : t> 10 s: primordial nucleosynthesis remain photons, and a few electrons and non relativistic p, n in thermal equilibrium Deuterium 2 H is then the start of other fusion reactions, leading to light nuclei ends when

Nucleosynthesis No stable nuclei with A=5, 8, primordial nucleosynthesis ends here!

After that the universe is filled with photons, electrons and light nuclei in thermal equilibrium e - +p H(atom)+  slows down when ends for kT 0.3 eV, t=10 5 yr t>10 5 yr matter (neutral atoms) and radiation decouple no more Compton interaction with charged particles: Universe becomes transparent to radiation (photons) relic photons now cooled down to Cosmic Microwave Background (CMB)

BIG BANG sec sec sec sec 100 sec 300’000 yr 10 9 yr 15x10 9 yr gravity separates EW Weak+Elec inflation ends quarks p, n p, n He formation of atoms galaxy formation today normal expansion

COBE

T=2.735 K waves/cm intensity, erg/cm 2 sr sec cm -1 black body, Planck Relic of the early universe

WMAP (NASA)

WMAP CMB