Introductionto Cosmology
Lecture 8
Cyburt+ 2015
Nollett & Burles 2000
The lightest elements are created
FIG. 1. Primordial abundances of the light nuclides as a function of cosmic baryon content, as
predicted by SBBN (“Schramm plot”). These results assume Nν = 3 and the current measurement
of the neutron lifetime τn = 880.3 ± 1.1 s. Curve widths show 1− σ errors.
D
H= 2.579×10−5
!
1010η
6.10
"−1.60#Nν
3.0
$0.395!
GN
GN,0
"0.95#τn
880.3s
$0.41
× [p(n, γ)d]−0.19 [d(d, n)3He]−0.53 [d(d, p)t]−0.47
× [d(p, γ)3He]−0.31
[3He(n, p)t]0.023
[3He(d, p)4He]−0.012
(14)
3He
H= 9.996×10−6
!
1010η
6.10
"−0.59#Nν
3.0
$0.14!
GN
GN,0
"0.34#τn
880.3s
$0.15
× [p(n, γ)d]0.088 [d(d, n)3He]0.21 [d(d, p)t]−0.27
× [d(p, γ)3He]0.38 [3He(n, p)t]−0.17 [3He(d, p)4He]−0.76 [t(d, n)4He]−0.009 (15)
7Li
H= 4.648×10−10
!
1010η
6.10
"2.11#Nν
3.0
$−0.284!
GN
GN,0
"−0.73#τn
880.3s
$0.43
20
Cyburt+ 2015
L Kewley
Aver+ 2015
BBN theory confronts observations 2015
Cooke 14
Sbordone 10
Aver 15
Quasar Absorption Line Spectroscopy
Energy Levels
15 *5-&"6+3) 7+8'+&.89)
Energy Levels
15 *5-&"6+3) 7+8'+&.89)
blue-shift of 82 km/s
Precision Measures of (D/H) [Cooke et al. 2017]
(D/H)DLA = (2.53± 0.03)⇥ 10�5
Precision Measures of (D/H) [Cooke et al. 2017]
(Random + Systematic Error)
100⌦b,0h2(BBN) = 2.235± 0.05
BBN theory confronts observations 2015
Cooke 14
Sbordone 10
Aver 15
Sbordone+ 2010
BBN theory confronts observations 2015
Cooke 14
Sbordone 10
Aver 15
N⌫ = 4
N⌫ = 3
N⌫ = 2
Cyburt+ 2015
Cooke+ 2014