1. Big Bang Nucleosynthesis: Theory vs. Observation
TASI 2009
Michael S. Turner
4 June 2009
Michael S Turner

2. Michael S Turner

3. Michael S Turner

4. 0.07 MeV 0.2 MeV 0.01 MeV 10 MeV 1 MeV D leads NSE, n/p~1/6
Thermal Equilibrium
BBN
Michael S Turner

5. BBN Reaction Network: the big 12
Michael S Turner

6. He-4 Prediction (95%): n ↔ p
ΔY = ± (τn) ± (th) ?
ΔY = ± Δτn/sec
τ(n) = ± 0.8 sec (±0.1%)
…but, Serebrov (2005): ± 0.8 sec (-0.8% or -6.5 σ)??##!!
Michael S Turner

7. D/H Prediction (95%): ±8%
d(d,n)He-3 and d(p,γ)He-3
Michael S Turner

8. p(n,γ)d, He-3(α,γ)Be-7, d(p,γ)He-3, d(d,n)He-3
Li-7 Prediction (95%): ±25%
p(n,γ)d, He-3(α,γ)Be-7, d(p,γ)He-3, d(d,n)He-3
Michael S Turner

9. Sharp contrast to stellar models
Reaction Cross Sections are measured where they are needed – no need to extrapolate.
Sharp contrast to stellar models
Michael S Turner

10. BBN Predictions (95% cl) Deuterium: baryometer!
He-4: go/no-go test of big bang
Li-7: consistency test;
stellar probe?
He-3: probe of chemical evolution
Michael S Turner

11. Light Element Abundances D, He-4 and Li-7
Deuterium: stars only destroy D – need pristine samples of the Universe
He-4: MS stars make He-4 – need old, metal poor stars
Li-7: also made by cosmic rays, destroyed by stars,
He-3: made and destroyed by stars, learn more about chemical evolution!
Michael S Turner

12. Michael S Turner

13. Detecting Deuterium Burles/Tytler, ApJ 499, 699 (1998)
Michael S Turner

14. O’Meara et al: 6 Deuterium Systems
D/H = 2.8 ± 0.3 x 10-5
BBN (Deuterium)
Ωbh2 = ± (D) ± (th)
YP = ± (D) ± (th) ± (τn)
 Li-7/H = 4.3 ± 0.5 x 10-10
-0.002?
Michael S Turner

15. Precision Cosmology Indeed!
CMB (first to second peak)
Ωbh2 = ±
vs.
BBN (Deuterium)
Ωbh2 = ±
~5% agreement
Ωb = ± 0.002
h = H0/100 km/s/Mpc ~ 0.7
Michael S Turner

16. He-4: 0.24x, Struggling for the 3rd Sig Fig
YP = ± (D) ± (th) ± (τn) ?
Michael S Turner

17. He-4: 0.24x, Struggling for the 3rd Sig Fig
YP = ± (D) ± (th) ± (τn) ?
Biggest issue: control of systematic error (see Peimbert, arXiv: )
State of the art, based upon extragalactic HII regions, Peimbert et al, ApJ 666, 636 (2007): YP = ± 0.003
Concordance with D/BBN prediction
Michael S Turner

18. Li-7: Not as simple as once thought
Li-7/H (D/H) = 4.3 ± 0.5 x 10-10
Spite plateau: Li-7/H = 1.3 ± 0.3 x 10-10
Factor of 3 discrepancy (for ~10 years)!
Possible explanation: Korn et al, Nature 442, 657 (2006): astration by gravitational settling
Inferred value by Korn et al : (3.5 ± 0.8) x 10-10
Michael S Turner

19. Selected BBN References
Recent reviews
Schramm/Turner, RMP 70, 303 (1998)
Steigman, ARNPS 57, 463 (2007)
Predicted abundances and uncertainties
Nollett/Burles, PRD 61, (2000)
Burles/Nollett/Turner, ApJ 552, L1 (2001)
Lopez/Turner, PRD 59, (1999)
Cyburt, PRD 70, (2004)
Serpico, JCAP 0412 (2004) 010
Serebrov et al, PLB 605, 72 (2005)
Deuterium
O’Meara et al, ApJ 649, L61 (2006)
Michael S Turner

20. Mapping depends upon cosmological parameters (good news!)
CMB anisotropy is a non-trivial map of density inhomogeneity to temperature fluctuations:
Mapping depends upon cosmological parameters (good news!)
ΩMh2
Michael S Turner

21. Relativistic Degrees of Freedom
All SM Particles
Quark/Hadron
γ/neutrinos
e± pairs
Michael S Turner

22. Neutrino Counting BBN (pre-LEP): Nν < 4
Lab (LEP): Nν = ± 0.012
BBN: Nν < 3.2 (95%)
CMB: Nν = 4.4 ± 1.5
Michael S Turner

23. BBN: GR Independent Quenched Reactor Carroll/Kaplinghat, PRD 65, 063507 (2002)
Michael S Turner

24. “Precision Cosmology” with SDSS + WMAP: concordance model
Standard Hot Big Bang of the 1970s
Flat, accelerating Universe
Atoms, exotic dark matter & dark energy
Consistent with inflation
Precision set of cosmological parameters
Ω0 = ± (uncurved)
ΩM = 0.28 ± 0.013
ΩB = ± 0.002
ΩΛ = 0.72 ± 0.02
H0 = 70 ± 1.3 km/s/Mpc
t0 = ± 0.12 Gyr
Nν = 4.4 ± 1.5
Consistent with all data, laboratory and cosmological!
Michael S Turner