Msc QFFF
Particle Cosmology
Course
Carlo Contaldi
[email protected]
Rm 608H
Aims and Objectives:
• Provide a self-contained foundation in
modern Cosmology
• Provide an advanced course in
Cosmology
• Allow the student to understand current
research in the field
• Provide the framework for connecting
theory to main observables in modern
cosmology
Course Textbooks
• Gravitation and Cosmology – Steven Weinberg
Good technical intro to GR with application to
Cosmology and black holes etc.
• The Early Universe – E. Kolb & M. Turner
Self Contained review of thermodynamics and
particle cosmology. Sometimes archaic but still
relevant.
• Modern Cosmology – Scott Dodelson
Good on modern perturbation theory notation
etc. bit superficial on the particle side.
• Physical Foundations of Cosmology – Vlacheslav
Mukhanov
Technical textbook for graduate students and
above.
Course Webpage
http://www3.imperial.ac.uk/theoreticalphysics/
postgraduatestudy/mastersdegree/courses/
cosmology
•GR
•Thermodynamics
•Particle Physics
•Perturbation
Theory
Consistent
model of
Universe
Astrophysics
Predictions
Compare to
Observations
3
1/10th diameter of moon
Universe Scales
Object
Size
Solar System
~ 10 Au
Solar Neighbourhood
~ 1 light year ~ parsec
Milky way
~ 1 Kpc
Clusters of Galaxy
~ 1-10 Mpc
Hubble Patch
3000 Mpc
Object
Mass
Solar Mass (Msol)
1.989 x 1033 g
Milky Way
~ 107-11 Msol
Clusters of Galaxies
~ 1012-15 Msol
Critical Density
9.21 x 10-30 g cm-3 =
Λ
1.36 x 1011 Msol Mpc -3
• 1 pc = 3.262 light years = 3.09 x 1013 km
• Hubble rate = 72 km s-1 Mpc-1
The ‘Standard’ Cosmological
model: ΛCDM
Baryons
Dark Energy
Dark Matter
Photons
Photons
Baryons
Dark Matter
Dark Energy
• Universe is made up of mostly dark energy and matter
• Universe is very close to critical density (to within 10-5 me!!)
• Background of decoupled photons and neutrinos (~ 300
photons/ cubic cm)
• Background expansion appears to be accelerating, driven by
dark energy/cosmological constant?
• Thermal history understood up to nucleosynthesis
• radiation > matter > Λ epochs
1/10th diameter of moon
8
Modern cosmology is a field driven by
observations.
First observations in cosmology focused on determining the
background evolution of the universe: i.e. expansion history
Modern day equivalent:
Supernovae
observations
Observation of light element abundance tests theories of
particle interactions in early universe and expansion history
during nucleosynthesis.
Brief Thermal History of the
Universe
t = 13.2 Gyrs : Today
T = 2.7K
t = 5 Gyrs : Matter-Dark Energy equality?
Expansion begins to accelerate…
Λ
t = few Gyrs : Galaxies and clusters of galaxies
form.
“COLD”
t = 300,000  1 Gyrs : Cosmic Dark Ages until
first objects form and reionize the universe
t = 300,000 yrs : Photon decoupling (p+e-)
recombination (deionization), CMB photons released
1eV  LAST SCATTERING SURFACE
time
t = 100,000 yrs : Matter – Radiation equality
t = 100s : n+p  Neucleosynthesis H,D,T,He,
3He,Li
0.1MeV
t = 1x10-4 s : Quark condensation. Formation of
Hadrons
100 MeV
t = 1x10-10s : Electroweak phase transition
100GeV
t < 1x10 -10 s : Baryogenesis, matter/anti-matter
annihilation
> 100 GeV
t = 1x10-37-> -35s : GUT spontaneous symmetry
breaking?
t = 1x10-32s : Reheating/thermalization of empty
universe?
1018 GeV
-43
t<1x10 s : Planck Epoch - Universe emerges
from quantum era? Emerges Inflating?
?
“HOT”
…the universe today…
Course Outline
1.
Introduction
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2.
The Hot, Smooth Universe
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3.
Thermodynamics in Cosmology
Zeroth-Order Boltzmann Equation
Nucleosynthesis
Recombination
Relics species
Baryogenesis
The Perturbed Universe
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4.
Spherical Collapse
Relativistic Perturbation Theory
Perturbations in Matter
Perturbations in Radiation – Cosmic Microwave Background
Origin of Perturbations – Inflation
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5.
Times and distances in Cosmology
Newtonian Cosmology
Relativistic Cosmology
Big Bang Puzzles
Scalar Field Cosmology
Solution of Big Bang Puzzles
Inflaton Perturbations
[Advanced Topics]