1. Particle Physics and Cosmology
Baryon asymmetry

6. Boltzmann equation in terms of cross section.

7. dimensionless inverse temperature
m : particle mass
small x : particle is relativistic x<3
large x : particle is non-relativistic x>3
dimensionless
time variable
in units of
particle mass m

8. particle number per entropy

9. cold relic fraction
not necessarily order one !

10. cold relic abundance , mass and cross section
inversely proportional to cross section ,
plus logarithmic dependence of xf

11. baryon relics in baryon symmetric Universe
observed : Y = η ≈

12. baryons :
the matter of stars and humans
Ωb = 0.045

13. Abundancies of
primordial
light elements
from
nucleosynthesis
A.Coc

14. primordial abundances for three GUT models
present observations : 1σ He D Li
T.Dent,
S.Stern,…

15. present baryon number

17. anti-baryons in baryon asymmetric Universe

18. conserved baryon asymmetry
no baryon number violating processes in
standard model of particle physics at energy
below 1 GeV
baryon asymmetry must exist at T = 1 GeV

19. high temperature baryon problem

21. baryon number violation in standard model
baryon number is global symmetry of interactions in the standard model
violated by quantum anomaly ( no anomalies possible for local symmetries : corresponding charge , like electric charge , exactly conserved )
sphaleron processes generate strong baryon number violating processes at temperatures above GeV

22. baryon number violation in standard model
no chemical potential for baryon number

23. thermal equilibrium in absence of chemical potential

25. baryogenesis

27. Sakharov’s conditions for baryogenesis
baryon number violation interactions
charge conjugation violating interactions
CP – violating interactions
non – equilibrium process

28. baryon number violating process in Grand Unified Theories ( GUT )

29. baryon number violating process in Grand Unified Theories ( GUT )

30. not good enough :
B asymmetry will be washed out later
by sphaleron processes
no B-L asymmetry is produced

31. leptogenesis or late baryogenesis

32. leptogenesis ( B-L ) B – L is conserved quantum number in
standard model
sphaleron processes transmute lepton asymmetry into baryon asymmetry
a fraction of primordial B-L asymmetry appears as baryon asymmetry
primordial asymmetry protected from wash out by sphaleron processes
( B-L )

33. leptogenesis non – equilibrium decay of heavy neutrinos
non – equilibrium production after inflation during entropy production of the Universe

34. baryogenesis during electroweak phase transition ?

35. Sakharov’s conditions for baryogenesis during electroweak phase transition
baryon number violation interactions ☺
charge conjugation violating interactions ☺
CP – violating interactions ☺
non – equilibrium process ☺

37. cosmological phase transitions

38. cosmological phase transitions

44. first order cosmological phase transitions

45. chaos in the Universe

48. baryogenesis during electroweak phase transition
strongly first order electroweak phase transition can generate baryon asymmetry if CP violation is sufficiently strong
no efficient baryogenesis for weak first order phase transition, second order phase transition or crossover
presumably too little CP violation in SM ( not definitely settled )

49. electroweak “phase transition “ in standard model is crossover !
perhaps strong first order transition in
supersymmetric extensions of standard model

50. standard model of particle physics and cosmology
no candidate for dark matter
no baryon asymmetry
no massive neutrinos

51. standard model of particle physics and cosmology
prediction :
present Universe consists of
photons and
massless neutrinos