Histoire de l’univers infinite, finite, infinite,

Red shift of galaxies

Doppler H 0 =Hubble constant

 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 3.5x10 3 K) 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

+ Robert Dicke…

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

The horizon problem t=t 0 t’, c(R(t 0 )/R(t’))dt’ t=0 n<1, The fraction of the universe we see increases with time Question: how could portions of the universe with no causal contact in the early universe be in thermal equilibrium?

Possible explanation: inflation in the early universe Friedman-Lemaître Thermal equilibrium in volume small enough, evolving into present oservable universe

Where do the elements with A>4 come from? Up to A=55: fusion reactions in stars Above: neutron capture +  decay in stars, supernovae explosions Abundance of isotopes

Sources: 1) T. Fliessbach, Allgemeine Relavitätstheorie, Spektrum 2) P. Schneider, Extragalactic astrophysics and cosmology, Springer 3) A. Unsöld and B. Bascheck, The New Cosmos, Springer 4) S. Weinberg, Gravitation and cosmology, Wiley 6) M. Treichel, Teilchenphysik und Kosmologie, Springer 7) D. Perkins, Particle Asprophysics, Oxford