BIG BANG NUCLEOSYNTHESIS CONFRONTS COSMOLOGY AND PARTICLE PHYSICS Gary Steigman Departments of Physics and Astronomy Center for Cosmology and Astro-Particle Physics Ohio State University Horiba International Conference : COSMO/CosPA 2010 Tokyo, Japan, September 27 – October 1, 2010

Baryon Density Parameter :  B Note : Baryons  Nucleons  B  n N / n  ;  10     B = 274  B h 2 Hubble Parameter : H = H(z) In The Early Universe : H 2 α Gρ (η B not predicted (yet) by fundamental theory)

Pre - e ± Ann. : S 2 = G  R / G  R   N / 43 S ≠ 1 is a Probe of Non - Standard Physics Where :  N  (  R -  R ) /  and N  3 +  N Expansion Rate Parameter : S  H/ H If  R =  R, G BBN / G 0 = S 2 =  N 4 He is sensitive to S (ΔN ) ; D probes  B Post - e ± Ann. :  R /  R   N Where : N eff   N

“Standard” Big Bang Nucleosynthesis (SBBN) For An Expanding Universe Described By General Relativity, With S = 1 (ΔN = 0) The Relic Abundances of D, 3 He, 4 He, 7 Li depend on only one parameter : η B Big Bang Nucleosynthesis (BBN) : S ≠ 1 Relic Abundances depend on η B and S (ΔN )

* Do the BBN - predicted abundances agree with observationally - inferred primordial abundances ? Do the BBN and CMB values of  B agree ? Do the BBN and CMB values of ΔN agree ? Is ΔN BBN = ΔN CMB = 0 ? BBN (~ 3 Minutes), The CMB (~ 400 kyr), LSS (~ 10 Gyr) Provide Complementary Probes Of The Early Evolution Of The Universe

BBN Abundances of D, 3 He, 7 Li are RATE (DENSITY) LIMITED D, 3 He, 7 Li are potential BARYOMETERS SBBN – Predicted Primordial Abundances 7 Li 7 Be 4 He Mass Fraction Mostly H & 4 He

Post – BBN Evolution of the Relic Abundances As gas cycles through stars, D is only DESTROYED Stars burn H to 4 He (and produce heavy elements)  4 He INCREASES (along with CNO …) As gas cycles through stars, 3 He is DESTROYED, PRODUCED and, some prestellar 3 He SURVIVES Cosmic Rays and SOME Stars PRODUCE 7 Li BUT, 7 Li is DESTROYED in most stars

DEUTERIUM Is The Baryometer Of Choice The Post – BBN Evolution of D is Simple : As the Universe evolves, D is only DESTROYED  * Anywhere, Anytime : (D/H) t  (D/H) P * For Z << Z  : (D/H) t  (D/H) P (Deuterium Plateau) H  and D  are observed in Absorption in High – z, Low – Z, QSO Absorption Line Systems (QSOALS) (D/H) P is sensitive to the baryon density (   B −  )

Observations of Deuterium In 7 High - Redshift, Low - Metallicity QSOALS (Pettini et al. 2008) log (D/H) vs. Oxygen Abundance Where is the D – Plateau ?

log(10 5 (D/H) P ) = 0.45 ± 0.03   10 (SBBN) = 5.80 ± 0.27 log (D/H) vs. Oxygen Abundance

3 He/H vs. O/H Stellar Produced (?) 3 He Is Consistent With SBBN 3 He Observed In Galactic H  Regions ( 3 He/H) P for  B =  B (SBBN + D)

Izotov & Thuan 2010 Y vs. O / H 4 He Observed in Low – Z Extragalactic H  Regions

Y P ( IT10 ) = ± ±  Y P = ± Y vs. O / H

For SBBN (ΔN = 0) With 5 + log(D/H) P = 0.45 ± 0.03  Y P = ± Y P (OBS) − Y P (SBBN) = ±  Y P (OBS) = Y P ~ 1.4 σ

But ! Lithium – 7 Is A Problem [Li] ≡ 12 + log(Li/H) Where is the Lithium Plateau ? Asplund et al Boesgaard et al Aoki et al Lind et al Li/H vs. Fe/H SBBN

For BBN (with η 10 & ΔN (S) as free parameters) BBN Abundances Are Functions of η 10 & S (ΔN ) SBBN Predictions Agree With Observations Of D, 3 He, 4 He, But NOT With 7 Li

Isoabundance Contours for 10 5 (D/H) P & Y P Y P & y D  10 5 (D/H)

Y P & y D  10 5 (D/H) Isoabundance Contours for 10 5 (D/H) P & Y P

5 + log(D/H) P = 0.45 ± 0.03 & Y P = ±  η 10 = 6.07 ± 0.33 & ΔN = 0.62 ± 0.46  ΔN = ~ 1.3 σ For BBN (ΔN ≠ 0) With But, what about Lithium ?  G BBN / G 0 = 1.10 ± 0.07

Lithium Isoabundance Contours [Li] P = 12 + log(Li/H) )

Even for N  3, [Li] P > 2.6 [Li] P = 12 + log(Li/H) )

Lithium – 7 Is STILL A Problem [Li] ≡ 12 + log(Li/H) BBN [Li] OBS too low by ~ 0.5 – 0.6 dex

For ΔN = 0, is  B (CMB) =  B (SBBN) ? CMB Temperature Anisotropy Spectrum Depends On The Baryon Density For ΔN ≠ 0, is  B (CMB) =  B (BBN) ?

Likelihood Distributions For η 10 SBBNCMB SBBN & CMB Agree Within ~ 1.3 σ

Likelihood Distributions For η 10 BBNCMB BBN & CMB Agree At < 1 σ

At BBN, With η 10 & ΔN As Free Parameters ΔN (BBN) = 0.62 ± 0.46  ΔN (BBN) = ~ 1.3 σ At REC, With CMB (WMAP 7 Year Data) + LSS ΔN (REC) = 1.30 ± 0.87  ΔN (REC) = ~ 1.5 σ

BBNCMB Likelihood Distributions For N BBN & CMB Agree At < 1 σ

Likelihood Distributions For N BBNCMB N = 3 N = 4 (?) N (BBN) depends on Y P

Chronology of Primordial Helium Abundance Determinations

CMB Chronology Of The BBN – Inferred Values Of N

SBBN IS Consistent With D, 3 He, 4 He And Agrees With The CMB + LSS + H 0 CONCLUSION # 1 (But, Lithium Is A Problem !) Post – BBN Decay of Massive Particles ? Annihilation of Dark Matter Relics ? Li depleted / diluted in Pop  Stars ?

Non - standard BBN (ΔN ≠ 0, S ≠ 1) IS Consistent With D, 3 He, & 4 He And With The CMB + LSS (But, not 7 Li) CONCLUSION # 2 * BBN + CMB Combined Can Constrain Non-standard Cosmology & Particle Physics

Entropy (CMB Photon) Conservation * In a comoving volume, N  = N B / η B * For conserved baryons, N B = constant * Comparing η B at BBN and at Recombination  N  (REC) / N  (SBBN) = 0.94 ± 0.05  N  (REC) / N  (BBN) = 0.98 ± 0.06 Comparing BBN And The CMB

“Extra” Radiation Density ? Example : Late decay of a massive particle Pre - e ± Ann. : (ρ R / ρ R ) BBN =  N Post - e ± Ann. : (ρ R / ρ R ) REC =  N In the absence of the creation of new radiation (via decay ?), (ρ R / ρ R ) BBN = (ρ R / ρ R ) REC Comparing ΔN at BBN and at Recombination  (ρ R / ρ R ) REC − (ρ R / ρ R ) BBN = 0.07 ± 0.14

For ΔN ≈ 0, BBN (D, 3 He, 4 He) Agrees With The CMB + LSS CONCLUSIONS BBN + CMB + LSS Can Constrain Cosmology & Particle Physics (But, Lithium Is A Problem !)

CHALLENGES Why is the spread in D abundances so large ? Why is 3 He/H uncorrelated with O/H and / or R ? What (how big) are the systematic errors in Y P ? Are there observing strategies to reduce them ? What is the primordial abundance of 7 Li ( 6 Li) ? More data is needed !