Primordial Nucleosynthesis - The Origin of the Lightest Elements
Marcel Krause Institute for Theoretical Physics (ITP), Karlsruhe Institute of Technology (KIT)
Institute for Theoretical Physics May 13, 2019
The Big Bang Theory in a Nutshell Primordial Nucleosynthesis - Overview Primordial Nucleosynthesis – Processes Measurements of the Abundance of the Lightest Elements Results of the Measurements
KIT – University of the State of Baden-Wuerttemberg and National Research Center of the Helmholtz Association www.kit.edu The Big Bang Theory in a Nutshell
geometrization of gravity:
May 13, 2019 M. Krause: Primordial Nucleosynthesis – The Origin of the Lightest Elements ITP, KIT 2 The Big Bang Theory in a Nutshell
geometrization of gravity: Einstein Field Equations
: Ricci tensor (curvature of space-time) : Ricci scalar (curvature of space-time) : metric tensor (metric of space-time) : Einstein tensor (manifold) : energy-momentum tensor (“source” of the curvature of space-time) : cosmological constant (vacuum state dark energy) : gravitational constant : speed of light
May 13, 2019 M. Krause: Primordial Nucleosynthesis – The Origin of the Lightest Elements ITP, KIT 3 The Big Bang Theory in a Nutshell
important parameters for an expanding universe: scale factor proper (physical) distance co-moving (reference) distance (per definition, today we have )
May 13, 2019 M. Krause: Primordial Nucleosynthesis – The Origin of the Lightest Elements ITP, KIT 4 The Big Bang Theory in a Nutshell
important parameters for an expanding universe: scale factor proper (physical) distance co-moving (reference) distance (per definition, today we have )
Hubble parameter today:
May 13, 2019 M. Krause: Primordial Nucleosynthesis – The Origin of the Lightest Elements ITP, KIT 5 The Big Bang Theory in a Nutshell
important parameters for an expanding universe: scale factor proper (physical) distance co-moving (reference) distance (per definition, today we have )
Hubble parameter today:
normalized spatial curvature parameter
May 13, 2019 M. Krause: Primordial Nucleosynthesis – The Origin of the Lightest Elements ITP, KIT 6 The Big Bang Theory in a Nutshell
critical density for :
(today roughly 5 hydrogen atoms per m³)
May 13, 2019 M. Krause: Primordial Nucleosynthesis – The Origin of the Lightest Elements ITP, KIT 7 The Big Bang Theory in a Nutshell
critical density for :
(today roughly 5 hydrogen atoms per m³)
evolution of the universe:
Parametrized Friedmann Lemaître Equations
: energy densities of radiation (R), matter (M), curvature (k) and the vacuum ( )
May 13, 2019 M. Krause: Primordial Nucleosynthesis – The Origin of the Lightest Elements ITP, KIT 8 The Big Bang Theory in a Nutshell
critical density for :
(today roughly 5 hydrogen atoms per m³)
evolution of the universe:
Parametrized Friedmann Lemaître Equations
: energy densities of radiation (R), matter (M), curvature (k) and the vacuum ( )
primordial nucleosynthesis!
May 13, 2019 M. Krause: Primordial Nucleosynthesis – The Origin of the Lightest Elements ITP, KIT 9 Primordial Nucleosynthesis - Overview
also known as Big Bang nucleosynthesis (BBN)
May 13, 2019 M. Krause: Primordial Nucleosynthesis – The Origin of the Lightest Elements ITP, KIT 10 Primordial Nucleosynthesis - Overview
also known as Big Bang nucleosynthesis (BBN)
explains the creation of the lightest elements (H, d, ³He, 4He, 7Li) directly after the Big Bang
temperature of the universe: between 1011 K and 109 K
May 13, 2019 M. Krause: Primordial Nucleosynthesis – The Origin of the Lightest Elements ITP, KIT 11 Primordial Nucleosynthesis - Overview
also known as Big Bang nucleosynthesis (BBN)
explains the creation of the lightest elements (H, d, ³He, 4He, 7Li) directly after the Big Bang
temperature of the universe: between 1011 K and 109 K
age of the universe: between 0.01 s and 3 min after the Big Bang famous “first three minutes” of the universe (cf. Weinberg etc.)
May 13, 2019 M. Krause: Primordial Nucleosynthesis – The Origin of the Lightest Elements ITP, KIT 12 Primordial Nucleosynthesis - Overview temperature
2.725 K
105 K CMB
109 K
1012 K
May 13, 2019 M. Krause: Primordial Nucleosynthesis – The Origin of the Lightest Elements ITP, KIT 13 Primordial Nucleosynthesis - Motivations
BBN is strongly supported by the Big Bang theory
explanation of the origin of the lightest elements
May 13, 2019 M. Krause: Primordial Nucleosynthesis – The Origin of the Lightest Elements ITP, KIT 14 Primordial Nucleosynthesis - Motivations
origin of the lightest elements (H, d, ³He, 4He, 7Li)
May 13, 2019 M. Krause: Primordial Nucleosynthesis – The Origin of the Lightest Elements ITP, KIT 15 Primordial Nucleosynthesis - Motivations
origin of the lightest elements (H, d, ³He, 4He, 7Li)
May 13, 2019 M. Krause: Primordial Nucleosynthesis – The Origin of the Lightest Elements ITP, KIT 16 Primordial Nucleosynthesis - Motivations
BBN is strongly supported by the Big Bang theory
explanation of the origin of the lightest elements
verifiable through experimental observations
May 13, 2019 M. Krause: Primordial Nucleosynthesis – The Origin of the Lightest Elements ITP, KIT 17 Primordial Nucleosynthesis - Motivations
BBN is strongly supported by the Big Bang theory
explanation of the origin of the lightest elements
verifiable through experimental observations
determination of the baryonic energy density
determination of the ratio of baryons and photons
Ratio of Baryons and Photons
May 13, 2019 M. Krause: Primordial Nucleosynthesis – The Origin of the Lightest Elements ITP, KIT 18 Primordial Nucleosynthesis – Four Stages
Stage 0: Quark Gluon Plasma
quasi-free quarks and gluons (free of confinement)
equilibrium state
terminates in hadronization formation of protons and neutrons
May 13, 2019 M. Krause: Primordial Nucleosynthesis – The Origin of the Lightest Elements ITP, KIT 19 Primordial Nucleosynthesis – Four Stages
Stage I: Thermodynamic Equilibrium
dominant particles:
equilibrium state between protons and neutrons continuous transformation via the weak interaction
May 13, 2019 M. Krause: Primordial Nucleosynthesis – The Origin of the Lightest Elements ITP, KIT 20 Primordial Nucleosynthesis – Four Stages
Stage I: Thermodynamic Equilibrium
difference in rest energy
May 13, 2019 M. Krause: Primordial Nucleosynthesis – The Origin of the Lightest Elements ITP, KIT 21 Primordial Nucleosynthesis – Four Stages
Stage I: Thermodynamic Equilibrium
difference in rest energy
proton and neutron are two states of one isospin doublet
Boltzmann Distribution in Thermal Equilibrium : Boltzmann constant
connection between neutron-proton ratio and statistical physics
May 13, 2019 M. Krause: Primordial Nucleosynthesis – The Origin of the Lightest Elements ITP, KIT 22 Primordial Nucleosynthesis – Four Stages
Stage I: Thermodynamic Equilibrium
reaction rate of the weak processes: ( : Fermi constant)
May 13, 2019 M. Krause: Primordial Nucleosynthesis – The Origin of the Lightest Elements ITP, KIT 23 Primordial Nucleosynthesis – Four Stages
Stage I: Thermodynamic Equilibrium
reaction rate of the weak processes: ( : Fermi constant) expansion rate of the universe:
May 13, 2019 M. Krause: Primordial Nucleosynthesis – The Origin of the Lightest Elements ITP, KIT 24 Primordial Nucleosynthesis – Four Stages
Stage I: Thermodynamic Equilibrium
reaction rate of the weak processes: ( : Fermi constant) expansion rate of the universe:
ratio of reaction and expansion rates:
weak processes freeze out at roughly
neutron-proton ratio stabilizes and the equilibrium is broken
May 13, 2019 M. Krause: Primordial Nucleosynthesis – The Origin of the Lightest Elements ITP, KIT 25 Primordial Nucleosynthesis – Four Stages
Stage II: Freeze-Out of the Weak Processes
thermodynamic equilibrium between neutrons and protons breaks
decay of free neutrons
Neutron-Proton Ratio at the Freeze-Out Temperature
May 13, 2019 M. Krause: Primordial Nucleosynthesis – The Origin of the Lightest Elements ITP, KIT 26 Primordial Nucleosynthesis – Four Stages
Stage III: Beta Decay of the Free Neutrons
mean lifetime of free neutrons:
Decay Process of Free Neutrons
May 13, 2019 M. Krause: Primordial Nucleosynthesis – The Origin of the Lightest Elements ITP, KIT 27 Primordial Nucleosynthesis – Four Stages
Stage III: Beta Decay of the Free Neutrons
mean lifetime of free neutrons:
Decay Process of Free Neutrons
no light elements are produced yet why?
May 13, 2019 M. Krause: Primordial Nucleosynthesis – The Origin of the Lightest Elements ITP, KIT 28 Primordial Nucleosynthesis – Four Stages
deuterium (d) is the next-to-lightest isotope to be produced
May 13, 2019 M. Krause: Primordial Nucleosynthesis – The Origin of the Lightest Elements ITP, KIT 29 Primordial Nucleosynthesis – Four Stages
deuterium (d) is the next-to-lightest isotope to be produced
binding energy of deuterium:
ratio of photons with the same energy at (high-end tail):
May 13, 2019 M. Krause: Primordial Nucleosynthesis – The Origin of the Lightest Elements ITP, KIT 30 Primordial Nucleosynthesis – Four Stages
deuterium (d) is the next-to-lightest isotope to be produced
binding energy of deuterium:
ratio of photons with the same energy at (high-end tail):
remember: baryon-to-photon ratio is
for each produced deuteron, one high-energy photon is present
thermal equilibrium between deuteron production and spallation
neither stable deuterium nor the other light elements can be produced yet stable deuterium is needed for other elements: “deuterium bottleneck”
May 13, 2019 M. Krause: Primordial Nucleosynthesis – The Origin of the Lightest Elements ITP, KIT 31 Primordial Nucleosynthesis – Four Stages
Stage IV: Primordial Nucleosynthesis
free neutrons continue to decay:
Neutron-Proton Ratio at the Beginning of BBN
May 13, 2019 M. Krause: Primordial Nucleosynthesis – The Origin of the Lightest Elements ITP, KIT 32 Primordial Nucleosynthesis – Four Stages equilibrium freeze-out free n decay BBN
thermal equilibrium without freeze-out
May 13, 2019 M. Krause: Primordial Nucleosynthesis – The Origin of the Lightest Elements ITP, KIT 33 Primordial Nucleosynthesis – Processes
Production of Deuterons
May 13, 2019 M. Krause: Primordial Nucleosynthesis – The Origin of the Lightest Elements ITP, KIT 34 Primordial Nucleosynthesis – Processes
Production of Deuterons
Production of Tritons
May 13, 2019 M. Krause: Primordial Nucleosynthesis – The Origin of the Lightest Elements ITP, KIT 35 Primordial Nucleosynthesis – Processes
Production of Deuterons
Production of Tritons
Production of Helium Isotopes
May 13, 2019 M. Krause: Primordial Nucleosynthesis – The Origin of the Lightest Elements ITP, KIT 36 Primordial Nucleosynthesis – Processes
May 13, 2019 M. Krause: Primordial Nucleosynthesis – The Origin of the Lightest Elements ITP, KIT 37 Primordial Nucleosynthesis – Processes
deuterium bottleneck
May 13, 2019 M. Krause: Primordial Nucleosynthesis – The Origin of the Lightest Elements ITP, KIT 38 Primordial Nucleosynthesis – Processes
production of the lightest elements (H, d, ³He, 4He, 7Li)
May 13, 2019 M. Krause: Primordial Nucleosynthesis – The Origin of the Lightest Elements ITP, KIT 39 Primordial Nucleosynthesis – Processes
production of the lightest elements (H, d, ³He, 4He, 7Li) what about the others?
May 13, 2019 M. Krause: Primordial Nucleosynthesis – The Origin of the Lightest Elements ITP, KIT 40 Primordial Nucleosynthesis – Processes
production of the lightest elements decays to 7Li with (H, d, ³He, 4He, 7Li) what about the others?
decays to 3He with
decays to p with
May 13, 2019 M. Krause: Primordial Nucleosynthesis – The Origin of the Lightest Elements ITP, KIT 41 Primordial Nucleosynthesis – Processes
all dominant processes terminate in 4He second most common atom in the universe
May 13, 2019 M. Krause: Primordial Nucleosynthesis – The Origin of the Lightest Elements ITP, KIT 42 Primordial Nucleosynthesis – Processes
all dominant processes terminate in 4He second most common atom in the universe
we had
Estimate of the Helium Abundance After the BBN
May 13, 2019 M. Krause: Primordial Nucleosynthesis – The Origin of the Lightest Elements ITP, KIT 43 Primordial Nucleosynthesis – Processes
all dominant processes terminate in 4He second most common atom in the universe
we had
Estimate of the Helium Abundance After the BBN
approximate abundance of the two lightest stable elements:
75% H, 25% 4He
May 13, 2019 M. Krause: Primordial Nucleosynthesis – The Origin of the Lightest Elements ITP, KIT 44 Primordial Nucleosynthesis – Processes
what about heavier elements?
May 13, 2019 M. Krause: Primordial Nucleosynthesis – The Origin of the Lightest Elements ITP, KIT 45 Primordial Nucleosynthesis – Processes
what about heavier elements?
production very unlikely: no stable elements with mass numbers 5 or 8 Coulomb wall increases drastically with increasing mass number
May 13, 2019 M. Krause: Primordial Nucleosynthesis – The Origin of the Lightest Elements ITP, KIT 46 Primordial Nucleosynthesis – Processes
fission
fusion
May 13, 2019 M. Krause: Primordial Nucleosynthesis – The Origin of the Lightest Elements ITP, KIT 47 Primordial Nucleosynthesis – Processes
fission
fusion
May 13, 2019 M. Krause: Primordial Nucleosynthesis – The Origin of the Lightest Elements ITP, KIT 48 Primordial Nucleosynthesis – Processes
prediction of abundance of all light elements during/after the BBN relative abundance relative
cosmic time in s
May 13, 2019 M. Krause: Primordial Nucleosynthesis – The Origin of the Lightest Elements ITP, KIT 49 Primordial Nucleosynthesis – Processes
prediction of abundance of all light elements during/after the BBN
roughly 75% H roughly 25% 4He d/H ≈ 10-5 3He/H ≈ 10-6
7Li/H ≈ 10-10 relative abundance relative
valid for one chosen
cosmic time in s
May 13, 2019 M. Krause: Primordial Nucleosynthesis – The Origin of the Lightest Elements ITP, KIT 50 Primordial Nucleosynthesis – Processes
variation of the baryon-photon ratio relative abundance relative
May 13, 2019 M. Krause: Primordial Nucleosynthesis – The Origin of the Lightest Elements ITP, KIT 51 Primordial Nucleosynthesis – Processes
variation of the baryon-photon ratio
Effect on 4He Production higher : higher n/p ratio
earlier production due to more n relative abundance relative
May 13, 2019 M. Krause: Primordial Nucleosynthesis – The Origin of the Lightest Elements ITP, KIT 52 Primordial Nucleosynthesis – Processes
variation of the baryon-photon ratio
Effect on 4He Production higher : higher n/p ratio earlier production due to more n
Effect on d Production higher : fewer high-energy photons
earlier synthesis but dense universe relative abundance relative
May 13, 2019 M. Krause: Primordial Nucleosynthesis – The Origin of the Lightest Elements ITP, KIT 53 Primordial Nucleosynthesis – Processes
variation of the baryon-photon ratio
Effect on 4He Production higher : higher n/p ratio earlier production due to more n
Effect on d Production higher : fewer high-energy photons
earlier synthesis but dense universe relative abundance relative
Effect on 7Li Production lower : more frequent decay to 4He higher : earlier synthesis
May 13, 2019 M. Krause: Primordial Nucleosynthesis – The Origin of the Lightest Elements ITP, KIT 54 Primordial Nucleosynthesis – Processes
measuring the abundance of the elements fixes
Motivations: confirms the Big Bang theory determines and indicates consistency of the BBN
over ten orders of magnitude relative abundance relative
May 13, 2019 M. Krause: Primordial Nucleosynthesis – The Origin of the Lightest Elements ITP, KIT 55 Primordial Nucleosynthesis – Processes
measuring the abundance of the elements fixes
Motivations: confirms the Big Bang theory determines and indicates consistency of the BBN over ten orders of magnitude
Methodology:
relative abundance relative measurements yield the horizontals in the plots point(s) of intersection indicate the measured value of
May 13, 2019 M. Krause: Primordial Nucleosynthesis – The Origin of the Lightest Elements ITP, KIT 56 Measurements of 4He
stellar nucleosynthesis: amount of 4He increases compared to the abundance after the BBN entanglement of primordial and stellar 4He production
May 13, 2019 M. Krause: Primordial Nucleosynthesis – The Origin of the Lightest Elements ITP, KIT 57 Measurements of 4He
stellar nucleosynthesis: amount of 4He increases compared to the abundance after the BBN entanglement of primordial and stellar 4He production
idea: search for stars with very low metallicity
Definition of Metallicity
prime candidate: “Blue Compact Dwarf Galaxies” (low metallicity, gas-rich, H-II region)
May 13, 2019 M. Krause: Primordial Nucleosynthesis – The Origin of the Lightest Elements ITP, KIT 58 Measurements of 4He
stellar nucleosynthesis: amount of 4He increases compared to the abundance after the BBN entanglement of primordial and stellar 4He production
idea: search for stars with very low metallicity
Definition of Metallicity
prime candidate: “Blue Compact Dwarf Galaxies” (low metallicity, gas-rich, H-II region)
spectral analysis of the H-II regions reveals the approximate primordial amount of 4He
May 13, 2019 M. Krause: Primordial Nucleosynthesis – The Origin of the Lightest Elements ITP, KIT 59
Measurements of 4He
]
1
-
Å
2
-
cm
1
-
erg erg s
16
- flux flux [10
wave length [nm]
May 13, 2019 M. Krause: Primordial Nucleosynthesis – The Origin of the Lightest Elements ITP, KIT 60 Measurements of 4He
relative amount Y of 4He is higher in stars with higher metallicity
May 13, 2019 M. Krause: Primordial Nucleosynthesis – The Origin of the Lightest Elements ITP, KIT 61 Measurements of 4He
relative amount Y of 4He is higher in stars with higher metallicity
measure the He-I recombination line at
spectral analysis yields Y over metallicity O/H
May 13, 2019 M. Krause: Primordial Nucleosynthesis – The Origin of the Lightest Elements ITP, KIT 62 Measurements of 4He
relative amount Y of 4He is higher in stars with higher metallicity
measure the He-I recombination line at
spectral analysis yields Y over metallicity O/H
extrapolation to zero metallicity
primordial amount of 4He
May 13, 2019 M. Krause: Primordial Nucleosynthesis – The Origin of the Lightest Elements ITP, KIT 63 Measurements of 4He
theoretical estimate:
experimental value (PDG): relative abundancerelative
May 13, 2019 M. Krause: Primordial Nucleosynthesis – The Origin of the Lightest Elements ITP, KIT 64 Measurements of d
no significant deuterium production after the BBN BBN is the main source of deuterium
May 13, 2019 M. Krause: Primordial Nucleosynthesis – The Origin of the Lightest Elements ITP, KIT 65 Measurements of d
no significant deuterium production after the BBN BBN is the main source of deuterium
deuterium is converted in stellar nucleosynthesis processes:
May 13, 2019 M. Krause: Primordial Nucleosynthesis – The Origin of the Lightest Elements ITP, KIT 66 Measurements of d
no significant deuterium production after the BBN BBN is the main source of deuterium
deuterium is converted in stellar nucleosynthesis processes:
measure the primordial d abundance through Lyman-α absorption lines
discrete energy levels of deuterium
May 13, 2019 M. Krause: Primordial Nucleosynthesis – The Origin of the Lightest Elements ITP, KIT 67 Measurements of d
no significant deuterium production after the BBN BBN is the main source of deuterium
deuterium is converted in stellar nucleosynthesis processes:
measure the primordial d abundance through Lyman-α absorption lines
discrete energy levels of deuterium
Ly-α line at (UV regime)
May 13, 2019 M. Krause: Primordial Nucleosynthesis – The Origin of the Lightest Elements ITP, KIT 68 Measurements of d
measure the primordial d abundance through Lyman-α absorption lines prime candidates: Quasar Absorption Systems (QAS)
May 13, 2019 M. Krause: Primordial Nucleosynthesis – The Origin of the Lightest Elements ITP, KIT 69 Measurements of d
measure the primordial d abundance through Lyman-α absorption lines prime candidates: Quasar Absorption Systems (QAS)
radiation emitted from quasars travels through interstellar clouds
increasing redshift z with increasing distance from the quasar:
May 13, 2019 M. Krause: Primordial Nucleosynthesis – The Origin of the Lightest Elements ITP, KIT 70 Measurements of d
measure the primordial d abundance through Lyman-α absorption lines prime candidates: Quasar Absorption Systems (QAS)
radiation emitted from quasars travels through interstellar clouds
increasing redshift z with increasing distance from the quasar:
the spectrum shows different Ly-α lines due to different redshifts z
the redshift is necessary since optical instruments are not sensitive enough in the UV regime
May 13, 2019 M. Krause: Primordial Nucleosynthesis – The Origin of the Lightest Elements ITP, KIT 71 Measurements of d
May 13, 2019 M. Krause: Primordial Nucleosynthesis – The Origin of the Lightest Elements ITP, KIT 72 Measurements of d
actual spectral analysis shows the Lyman-α forest
QAS object
distance relative flux [arbitrary units] flux [arbitrary relative
wave length [Angstroms]
May 13, 2019 M. Krause: Primordial Nucleosynthesis – The Origin of the Lightest Elements ITP, KIT 73 Measurements of d
actual spectral analysis shows the Lyman-α forest
May 13, 2019 M. Krause: Primordial Nucleosynthesis – The Origin of the Lightest Elements ITP, KIT 74 Measurements of d
actual spectral analysis shows the Lyman-α forest
QAS object
distance relative flux [arbitrary units] flux [arbitrary relative
wave length [Angstroms]
May 13, 2019 M. Krause: Primordial Nucleosynthesis – The Origin of the Lightest Elements ITP, KIT 75 Measurements of d
consider a single absorption line
flux [arbitrary units] flux [arbitrary relative flux [arbitrary units] flux [arbitrary relative
wave length [Angstroms]
May 13, 2019 M. Krause: Primordial Nucleosynthesis – The Origin of the Lightest Elements ITP, KIT 76 Measurements of d
consider a single absorption line
split the flux into the normalized flux of d and H
flux [arbitrary units] flux [arbitrary ratio yields the relative abundance
of d compared to H relative flux [arbitrary units] flux [arbitrary relative
wave length [Angstroms]
May 13, 2019 M. Krause: Primordial Nucleosynthesis – The Origin of the Lightest Elements ITP, KIT 77 Measurements of d
consider a single absorption line
split the flux into the normalized flux of d and H
flux [arbitrary units] flux [arbitrary ratio yields the relative abundance of d compared to H
caveats: due to the dominance of H, the difference in intensities is huge the flux at the absorption line of H
is practically vanishing relative flux [arbitrary units] flux [arbitrary relative
wave length [Angstroms]
May 13, 2019 M. Krause: Primordial Nucleosynthesis – The Origin of the Lightest Elements ITP, KIT 78 Measurements of d
consider a single absorption line
split the flux into the normalized flux of d and H
flux [arbitrary units] flux [arbitrary ratio yields the relative abundance of d compared to H
caveats: due to the dominance of H, the difference in intensities is huge the flux at the absorption line of H is practically vanishing
consider a lot of different Ly-α lines
from different sources relative flux [arbitrary units] flux [arbitrary relative
wave length [Angstroms]
May 13, 2019 M. Krause: Primordial Nucleosynthesis – The Origin of the Lightest Elements ITP, KIT 79 Measurements of d
consider a lot of different Ly-α lines from different sources
May 13, 2019 M. Krause: Primordial Nucleosynthesis – The Origin of the Lightest Elements ITP, KIT 80 Measurements of d
consider a lot of different Ly-α lines from different sources
more caveats for the measurements: the Ly-α lines for d and H are close to each other: Doppler shift of the Ly-α lines through rotation of the clouds reduces the resolution of the Ly-α forest quasars are required to be at a suitable distance in order to avoid overlaps of red-shifted Ly-α lines from d and H many quasars yield results with huge standard deviations
May 13, 2019 M. Krause: Primordial Nucleosynthesis – The Origin of the Lightest Elements ITP, KIT 81 Measurements of d
many quasars yield results with huge standard deviations
only 10 measurements are suitable for the current best-fit analysis
experimental value (PDG): relative abundancerelative
May 13, 2019 M. Krause: Primordial Nucleosynthesis – The Origin of the Lightest Elements ITP, KIT 82 Measurements of 3He
3He is constantly produced and converted in stellar nucleosynthesis processes
May 13, 2019 M. Krause: Primordial Nucleosynthesis – The Origin of the Lightest Elements ITP, KIT 83 Measurements of 3He
3He is constantly produced and converted in stellar nucleosynthesis processes
the only available measurements of the 3He abundance stem from regions within the solar system regions with very high metallicity not suitable for determining the primordial abundance of 3He
May 13, 2019 M. Krause: Primordial Nucleosynthesis – The Origin of the Lightest Elements ITP, KIT 84 Measurements of 3He
3He is constantly produced and converted in stellar nucleosynthesis processes
the only available measurements of the 3He abundance stem from regions within the solar system regions with very high metallicity not suitable for determining the primordial abundance of 3He
distinguishing 3He and 4He is technically very difficult abundance of 3He is not considered a suitable observable for the analysis of the BBN
May 13, 2019 M. Krause: Primordial Nucleosynthesis – The Origin of the Lightest Elements ITP, KIT 85 Measurements of 7Li
most suitable objects for measuring 7Li: population II stars (very old, low metallicity, thin convection layer)
May 13, 2019 M. Krause: Primordial Nucleosynthesis – The Origin of the Lightest Elements ITP, KIT 86 Measurements of 7Li
most suitable objects for measuring 7Li: population II stars (very old, low metallicity, thin convection layer)
spectroscopy of the stellar atmosphere: 7Li resonance doublets at
observation: “linear” dependence between 7Li and Fe abundance
extrapolation yields the primordial 7Li abundance
May 13, 2019 M. Krause: Primordial Nucleosynthesis – The Origin of the Lightest Elements ITP, KIT 87 Measurements of 7Li
Fe/H relative to the sun
May 13, 2019 M. Krause: Primordial Nucleosynthesis – The Origin of the Lightest Elements ITP, KIT 88 Measurements of 7Li
Fe/H relative to the sun
May 13, 2019 M. Krause: Primordial Nucleosynthesis – The Origin of the Lightest Elements ITP, KIT 89 Measurements of 7Li
caveat for the measurements: 7Li is converted for
Lithium Burning
May 13, 2019 M. Krause: Primordial Nucleosynthesis – The Origin of the Lightest Elements ITP, KIT 90 Measurements of 7Li
caveat for the measurements: 7Li is converted for
Lithium Burning expectation from WMAP
strong 7Li burning expected:
Li/H 7 7 approx. primordial Li
strong weak convection convection
surface temperature [K]
May 13, 2019 M. Krause: Primordial Nucleosynthesis – The Origin of the Lightest Elements ITP, KIT 91 Measurements of 7Li
caveat for the measurements: 7Li is converted for
Lithium Burning expectation from WMAP
strong conversion dominantly happens 7Li burning expected:
in the convection layer of the star Li/H 7 7 approx. primordial Li consider population II stars with weak surface convection
strong weak convection convection
surface temperature [K]
May 13, 2019 M. Krause: Primordial Nucleosynthesis – The Origin of the Lightest Elements ITP, KIT 92 Measurements of 7Li
experimental value (PDG):
uncertainties in the measurements are very high
experimental results are at odds
with predictions from BBN relative abundancerelative „cosmological lithium problem“
May 13, 2019 M. Krause: Primordial Nucleosynthesis – The Origin of the Lightest Elements ITP, KIT 93 Measurements of 7Li
the cosmological lithium problem is unsolved as of today
May 13, 2019 M. Krause: Primordial Nucleosynthesis – The Origin of the Lightest Elements ITP, KIT 94 Measurements of 7Li
the cosmological lithium problem is unsolved as of today
possible explanations for the “lithium gap” within the Standard Model (SM) are inconclusive [ A. Coc et al JCAP10(2014)050, arXiv:1403.6694 (astro-ph.CO) ]
portal for beyond the SM (BSM) physics
May 13, 2019 M. Krause: Primordial Nucleosynthesis – The Origin of the Lightest Elements ITP, KIT 95 Measurements of 7Li
the cosmological lithium problem is unsolved as of today
possible explanations for the “lithium gap” within the Standard Model (SM) are inconclusive [ A. Coc et al JCAP10(2014)050, arXiv:1403.6694 (astro-ph.CO) ]
portal for beyond the SM (BSM) physics
BSM explanations for the lithium gap are also inconclusive [ C. A. Bertulani et al EPJ Web of Conferences 184, 01002 (2018), arXiv:1802.03469 (nulc-th) ]
remains an open problem to be solved
May 13, 2019 M. Krause: Primordial Nucleosynthesis – The Origin of the Lightest Elements ITP, KIT 96 Combination of the Results
experimental best fit (PDG):
(95% CL)
with , also the baryonic energy relative abundancerelative density is determined
May 13, 2019 M. Krause: Primordial Nucleosynthesis – The Origin of the Lightest Elements ITP, KIT 97 Determination of – Method 1 via BBN
photon density at from black body radiation:
May 13, 2019 M. Krause: Primordial Nucleosynthesis – The Origin of the Lightest Elements ITP, KIT 98 Determination of – Method 1 via BBN
photon density at from black body radiation:
the baryonic energy density can now be calculated: reduced Hubble constant:
May 13, 2019 M. Krause: Primordial Nucleosynthesis – The Origin of the Lightest Elements ITP, KIT 99 Determination of – Method 1 via BBN
photon density at from black body radiation:
the baryonic energy density can now be calculated: reduced Hubble constant:
current best-fit value (PDG) at 95% CL:
baryons account for roughly 4% to 5% of the total energy density of the universe
May 13, 2019 M. Krause: Primordial Nucleosynthesis – The Origin of the Lightest Elements ITP, KIT 100 Determination of – Method 2 via CMB
measurements of the Cosmic Microwave Background (CMB) through Planck 2015 data directly yield:
May 13, 2019 M. Krause: Primordial Nucleosynthesis – The Origin of the Lightest Elements ITP, KIT 101 Determination of – Method 2 via CMB
measurements of the Cosmic Microwave Background (CMB) through Planck 2015 data directly yield:
from this, the baryon-photon ratio is calculated:
the CMB yields an independent cross-check of the results gained by analyzing the BBN
good agreement between the BBN and the CMB results
May 13, 2019 M. Krause: Primordial Nucleosynthesis – The Origin of the Lightest Elements ITP, KIT 102 Combination of the Results
experimental value through BBN:
experimental value through CMB: relative abundancerelative
good agreement between BBN and CMB results
May 13, 2019 M. Krause: Primordial Nucleosynthesis – The Origin of the Lightest Elements ITP, KIT 103 Hints of Dark Matter
measurements through BBN yield:
measurements through CMB yield: independent measurements
May 13, 2019 M. Krause: Primordial Nucleosynthesis – The Origin of the Lightest Elements ITP, KIT 104 Hints of Dark Matter
measurements through BBN yield:
measurements through CMB yield: independent measurements
on the other hand, measuring the full matter density yields:
most of the matter content of the universe is non-baryonic “dark” matter
May 13, 2019 M. Krause: Primordial Nucleosynthesis – The Origin of the Lightest Elements ITP, KIT 105 Hints of Dark Matter
May 13, 2019 M. Krause: Primordial Nucleosynthesis – The Origin of the Lightest Elements ITP, KIT 106 Conclusion the BBN describes the first three minutes of the universe
the relative abundance of the lightest elements is not arbitrary but can be calculated
theoretical predictions gained by the BBN are consistent over ten orders of magnitude
through spectral observations, the baryonic matter density can be measured in the framework of the BBN
independent measurements through the CMB provide a cross-check of the results gained by the BBN excellent agreement
the measured baryonic matter density is a hint towards dark matter
open questions with respect to the cosmological lithium problem (portal to BSM physics?)
May 13, 2019 M. Krause: Primordial Nucleosynthesis – The Origin of the Lightest Elements ITP, KIT 107 Thanks!
May 13, 2019 M. Krause: Primordial Nucleosynthesis – The Origin of the Lightest Elements ITP, KIT 108 May 13, 2019 M. Krause: Primordial Nucleosynthesis – The Origin of the Lightest Elements ITP, KIT 109 Figure References
https://cdn-images-1.medium.com/max/1000/1*0Rh6Fxy_B4rHxdjpbIwFFw.jpeg https://upload.wikimedia.org/wikipedia/commons/9/98/End_of_universe.jpg https://web.njit.edu/~gary/202/assets/fig2202.jpg https://en.wikipedia.org/wiki/Big_Bang_nucleosynthesis#/media/File:Nucleosynthesis_periodic_table.svg https://simple.wikipedia.org/wiki/Isotope#/media/File:Blausen_0530_HydrogenIsotopes.png https://www.researchgate.net/figure/The-n-p-ratio-as-a-function-of-comoving-temperature-parameter- Tcm-in-the-third-scenario_fig3_305186106 https://de.wikipedia.org/wiki/Kernfusion#/media/File:Deuterium-tritium_fusion.svg https://www.researchgate.net/figure/Atomic-particles-can-overcome-the-Coulomb-barrier-electrostatic- repulsion-at-much_fig1_282394950 https://en.wikipedia.org/wiki/Stellar_nucleosynthesis#/media/File:FusionintheSun.svg https://wmap.gsfc.nasa.gov/media/121236/121236_NewPieCharts720.png https://i0.wp.com/thecuriousjalebi.com/wp- content/uploads/2018/10/5dc15a58073122dfbb1db83934e49fdc.jpg?ssl=1
May 13, 2019 M. Krause: Primordial Nucleosynthesis – The Origin of the Lightest Elements ITP, KIT 110 Back-up slides
May 13, 2019 M. Krause: Primordial Nucleosynthesis – The Origin of the Lightest Elements ITP, KIT 111