• The Universe is expanding • The Universe is filled with radiation • The Early Universe was Hot & Dense The Early Universe was a Cosmic Nuclear Reactor! ~ 100 s after the Big Bang Primordial Nucleosynthesis ~ 1 - 10 Gyr LSS ~ 0.1 s after the Big Bang Neutrinos Decouple ~ 400 kyr after the Big Bang Relic Photons (CMB) are free Neutron Abundance vs. Time / Temperature p + e n + e … Rates set by n “Freeze – Out” ? Wrong! (n/p)eq BBN “Begins” Decay n measurements vs. time Statistical Errors versus Systematic Errors ! 885.7 0.8 sec BBN “Begins” at T 70 keV when n / p 1 / 7 Coulomb Barriers and absence of free neutrons terminate BBN at T 30 keV tBBN 4 24 min. Pre - BBN Only n & p Post - BBN Mainly H & 4He Baryon Density Parameter nN / n ; 10 = 274 Bh2 where : B B / c and : h H0 / 100 km / s / Mpc 0.7 Note : Baryons Nucleons Evolution of mass - 2 10 More nucleons less D Two pathways to mass - 3 More nucleons less mass - 3 Two pathways to mass - 7 BBN abundances of masses – 6, 9 – 11 Abundances Are Very Small ! BBN – Predicted Primordial Abundances BBN Abundances of D, 3He, 7Li are RATE (Density) LIMITED 7Li 7Be D, 3He, 7Li are potential BARYOMETERS Use BBN ( D / H ) P vs. 10 to constrain B Predict (D/H)P “Measure” ( D / H ) P Infer B (B) at 20 Min. Y is very weakly dependent on the nucleon abundance All / most neutrons are incorporated in 4He n/p 1/7 Y 0.25 Y 4He Mass Fraction Y 4y/(1 + 4y) y n(He)/n(H) YP DOES depend on the competition between Γwk & H • 4He (mass fraction Y) is NOT Rate Limited • 4He IS n/p Limited Y is sensitive to the EXPANSION RATE ( H 1/2 ) • Expansion Rate Parameter : S H´/ H S H´/ H (´ / )1/2 (1 + 7N / 43)1/2 where ´ + N and N 3 + N The Expansion Rate (H Hubble Parameter) Is A Probe Of Non-Standard Physics • S2 (H/ H)2 = G/ G 1 + 7N / 43 * S can be parameterized by N N ( - ) / and N 3 + N NOTE : G/ G = S2 1 + 7N / 43 • 4He is sensitive to S (N) ; D probes B 4He is an early – Universe Chronometer Y vs. D / H N = 2, 3, 4 (S = 0.91, 1.00, 1.08) Y 0.013 N 0.16 (S – 1) Isoabundance Contours for 105(D/H)P & YP YP & yD 105 (D/H) 4.0 2.0 3.0 0.25 0.24 0.23 D & 4He Isoabundance Contours Kneller & Steigman (2004) Kneller & Steigman (2004) & Steigman (2007) yDP 105(D/H)P = 46.5 (1 ± 0.03) D-1.6 YP = (0.2386 ± 0.0006) + He / 625 y7 1010(7Li/H) = (1.0 ± 0.1) (LI)2 / 8.5 where : D 10 – 6 (S – 1) He 10 – 100 (S – 1) Li 10 – 3 (S – 1) Post – BBN Evolution • As gas cycles through stars, D is only DESTROYED • As gas cycles through stars, 3He is DESTROYED , PRODUCED and, some 3He SURVIVES • Stars burn H to 4He (and produce heavy elements) 4He INCREASES (along with CNO) • Cosmic Rays and SOME Stars PRODUCE 7Li BUT, 7Li is DESTROYED in most stars Observing D in QSOALS Ly - Absorption Towards Primordial Deuterium Observations of Deuterium In 7 High-Redshift, Low-Metallicity QSO Absorption Line Systems 105(D/H)P = 2.7 ± 0.2 (Weighted Mean of D/H) (Weighted mean of log (D/H) 105(D/H)P = 2.8 ± 0.2) (D /H)obs + BBNpred 10 = 6.0 ± 0.3 BBN V. Simha & G. S. CMB Temperature Anisotropy Spectrum (T2 vs. ) Depends On The Baryon Density 10 = 4.5, 6.1, 7.5 V. Simha & G. S. The CMB provides an early - Universe Baryometer CMB + LSS 10 10 = 6.1 ± 0.2 Likelihood CMB V. Simha & G. S. Primordial Deuterium Predicted BBN + CMB/LSS 105(D/H)P = 2.6 ± 0.1 BBN (~ 20 min) & CMB (~ 380 kyr) AGREE 10 Likelihoods CMB BBN V. Simha & G. S. Oxygen Gradient In The Galaxy 3He Measured In Galactic HII Regions SBBN 3He Measured In Galactic HII Regions SBBN 4He Observed In Extragalactic H Regions As O/H 0, Y 0 SBBN Prediction : YP = 0.248 K. Olive YP = 0.240 ± 0.006 ( Or : YP < 0.255 @ 2 σ ) SBBN 10 Likelihoods from D and 4He AGREE ? to be continued … But ! Lithium – 7 Is (ALSO) A Problem [Li] ≡ 12 + log(Li/H) [Li]SBBN 2.6 – 2.7 [Li]OBS 2.1 Li too low ! Baryon Density Determinations: Consistent ? Late - Decaying NLSP ? ? N < 3 ? Observational Uncertainties Or New Physics? YP vs. (D/H)P for N = 2, 3, 4 N 3 ? A Non-Standard BBN Example (Neff < 3) Late Decay of a Massive Particle Kawasaki, Kohri & Sugiyama & Low Reheat Temp. (TR MeV) Relic Neutrinos Not Fully (Re) Populated Neff < 3 Isoabundance Contours for 105(D/H)P & YP YP & yD 105 (D/H) 4.0 3.0 2.0 0.25 0.24 0.23 Kneller & Steigman (2004) N vs. 10 From BBN (D & 4He) ( YP < 0.255 @ 2 σ ) BBN Constrains N N < 4 N > 1 V. Simha & G. S. CMB Temperature Anisotropy Spectrum Depends on the Radiation Density R (S or N) N = 1, 3, 5 V. Simha & G. S. The CMB / LSS is an early - Universe Chronometer N Is Degenerate With mh2 The degeneracy can be broken - partially - by H0 (HST) and LSS 1 + zeq = m / R 1 + zeq ≈ 3200 V. Simha & G. S. CMB + LSS + HST Prior on H0 N vs. 10 CMB + LSS Constrain 10 V. Simha & G. S. Use the CMB + LSS to bound η10 and N Use BBN to predict YP , yDP , yLiP (solid black) Compare to the observed abundances (dashed) 4He Korn et al. 7Li D ? V. Simha & G. S. Even for N 3 Y + D H Li H 4.0 0.7 x 10 10 yLi 1010 (Li/H) 4.0 3.0 2.0 0.25 4.0 0.24 0.23 Li depleted / diluted in Pop stars ? Kneller & Steigman (2004) Alternative to N 3 (S 1) e Degeneracy (Non – Zero Lepton Number) YP & yD For e = e/kT 0 (more e than anti - e) 4.0 105 (D/H) 3.0 2.0 0.23 n/p exp ( m/kT e ) 0.24 n/p YP 0.25 YP probes D & 4He Isoabundance Contours Lepton Asymmetry Kneller & Steigman (2004) Kneller & Steigman (2004) & Steigman (2007) yDP 105(D/H)P = 46.5 (1 ± 0.03) D-1.6 YP = (0.2386 ± 0.0006) + He / 625 y7 1010(7Li/H) = (1.0 ± 0.1) (LI)2 / 8.5 where : D 10 + 5 e / 4 He 10 – 574 e / 4 Li 10 – 7 e / 4 e Degeneracy (Non – Zero Lepton Number) YP & yD 105 (D/H) For N = 3 : e = 2.0 3.0 0.23 0.035 0.026 & 10 4.0 = 5.9 0.4 (V. Simha & G. S.) 0.24 0.25 BBN Constraints (D & 4He) On e For N = 3 e = 0.035 ± 0.026 10 = 5.9 ± 0.3 V. Simha & G.S. Even With Non - Zero e Degeneracy, The 7Li Problem Persists yLi 1010 (7Li/H) [Li] = 2.6 0.7 Still ! 4.0 [Li] = 2.7 0.7 with CFO 2008 results Li depleted / diluted in Pop stars ? Or, Late Decay of (Charged) NLSP ? 4.0 2.0 3.0 0.23 0.24 0.25 BBN & The CBR Provide Complementary Probes Of The Early Universe Do predictions and observations of the baryon density parameter (B) and the expansion rate parameter (S or N) agree at 20 minutes and at 400 kyr ? BBN (D & 4He) & CMB + LSS + HST AGREE ! N vs. 10 CMB + LSS BBN V. Simha & G. S. Several consequences of the good agreement between BBN and CMB + LSS Entropy Conservation : N (CMB) / N (BBN) = 0.92 ± 0.07 Modified Radiation Density (late decay of massive particle) ρRCMB / ρRBBN = 1.07 +0.16 -0.13 Variation in the Gravitational Constant ? GBBN / G0 = 0.91 ± 0.07 ; GCMB / G0 = 0.99 ± 0.12 BBN + CMB + LSS Combined Fit N vs. 10 ( YP < 0.255 @ 2 σ ) N = 2.5 ± 0.4 10 = 6.1 ± 0.1 V. Simha & G.S. N & e BOTH FREE, BBN + CMB/LSS Consistent with e = 0 & N = 3 N = 3.3 ± 0.7 e = 0.056 ± 0.046 V. Simha & G.S. CONCLUSIONS BBN (D, 3He, 4He) Agrees With The CMB + LSS (For N ≈ 3 & e ≈ 0) (But, 7Li is a problem) BBN + CMB + LSS Combined Can Constrain Non-Standard Cosmology & Particle Physics