1. COSMOLOGY International Meeting of Fundamental Physics
(“Winter” meeting)
Santiago de Compostela, 2007
Eduard Massó
UAB/IFAE

2. Program The standard cosmological model The observed universe
Inflation. Neutrinos in cosmology
Emphasis on “Particles”

3. Science, vol. 315, 2007

4. Our universe is expanding
lights-years
ago
co-moving
distance
scale
today
redshift

5. Co-moving co-ordinates
On top: peculiar (real) velocities

6. Hubble’s law & Cosmological principle
Universe homogenous & isotropic
on large scales
Hubble parameter
(today)
Hubble’s discovery
Hubble’s law:

7. Expansion (or contraction) is inevitableRG + CP
Robertson-Walker metric
(homogeneity & isotropy)
Parameters:
Content
(matter+radiation)
Content too
(cosm. const.)
Parameters
are related
by eqs.
Spatial geometry

8. Cosmological equations
Friedmann eqs. 1 2a
1+2a -> 2b

9. Spatial geometry &Light propagation
Open
Closed
FLAT 3D

10. Spatial geometry &Light propagation

11. Luminosity distance Absolute luminosity E/time in rest frame
Measured flux
(E/time/area)
Luminosity distance

12. Hubble’s law
Exact:
Small z
Deceleration
parameter
That was kinematics

13. Cosmological constant contribution
Negative
pressure
+ any other component

14. Solution to cosmological eqs.
Equation of state
Assume i - dominance and
RD universe
MD universe.
CCD universe

15. Critical density Define Define also (Today)
Not energy-density contribution

16. Rewriting Friedmann eqs.
Cosmic sum rule
2a today
Notice signs

17. The future Diff. eq. + Initial conditions taken today
Eternal Expansion OR Recollapse ? EE 1 2 R EE 3 R

18. Distance - Redshift Co-moving distance to source: Where: Can neglect
Distance-redshift relation is function of

19. Age of the universe look-back time lifetime Flat univ. Our univ.
(Age crisis: Open universe gave too low lifetime)

20. Which universe ?

21. The past universe nucleosynthesis rad recombination mat cc equality
today
next

22. The hot universe Equilibrium thermodynamics number density
g= deg. of freedom
number density
energy density
pressure
distribution

23. Decoupling of species
Expansion:
Interaction:
rates

24. Phase transitions Symmetry restoring
2n order

25. Phase transitions
1st order

26. Conformal time

27. Particle Horizon
It is the physical distance photons can travel until a time t
Defines causal distance at a given time t

28. Program The standard cosmological model The observed universe
Inflation. Neutrinos in cosmology