1. INFLATIONARY UNIVERSE: A RELATIVISTIC NECESSITY ?
Giovanni Zanella
Studioso Senior dello Studium Patavinum
Università di Padova,
Dipartimento di Fisica e Astronomia

2. Relativistic kinetics
Wavefront of light at the time y t
Rigid rod
Flash of light at the time t =0 1 2 3
c t u
c t
c t
u y t
Stationary reference
u t x
Wavefront of light at the time t
Source of light

3. Cosmic muons crossing the terrestrial atmosphere
Starting point
660 m = u t
atmosphere top
15 km = u y t
Stationary reference
Dilated path of the muon at steady kinetic energy
sea level
t = mean life of the muon ( ~ 2.2  s )
u = velocity of the muon from the stationary reference ( ~ c)
y t = dilated mean life of the muon
u y t = dilated path of the muon
u y = velocity measured from the muon vs the stationary reference

4. Particles in mutual leaving
Stationary reference x
t = elapsed time for the comoving observer
u/2 = velocity of the particle with respect the stationary reference
u y = velocity measured from a particle with respect to the other one
u y t = dilated distance of the particle

5. Inflationary UniverseM R
Stationary reference
Particles in mutual leaving
Flatness condition

6. Expansion of the observable Universe
Radius (m)
STANDARD MODEL
1030
1010
10-10
NOW
Inflation
10-30
10-50
10-32
Time (s)
10-35
10-25
10-15
10-5
105
1015
Primordial fireball
Appearence of particles