Physics and astronomy

Introduction to Cosmology

Module code: 900F3
Level 7 (Masters)
15 credits in autumn teaching
Teaching method: Workshop, Lecture
Assessment modes: Unseen examination, Coursework

This module covers:

  • Observational Overview: in visible light and other wavebands; the cosmological principle; the expansion of the universe; particles in the universe.
  • Newtonian Gravity: the Friedmann equation; the fluid equation; the aceleration equation.
  • Geometry: flat, spherical and hyperbolic; infinite vs. observable universes; introduction to topology
  • Cosmological Models: solving equations for matter and radiation dominated expansions and for mixtures (assuming flat geometry and zero cosmological constant); variation of particle number density with scale factor; variation of scale factor with time and geometry.
  • Observational Parameters: Hubble, density, deceleration.
  • Cosmological Constant: fluid description; models with a cosmological constant.
  • The Age of the Universe: tests; model dependence; consequences
  • Dark Matter: observational evidence; properties; potential candidates (including MACHOS, neutrinos and WIMPS)
  • The Cosmic Microwave Background: properties; derivation of photo to baryon ratio; origin of CMB (including decoupling and recombination).
  • The Early Universe: the epoch of matter-radiation equality; the relation between temperature and time; an overview of physical properties and particle behaviour.
  • Nucleosynthesis: basics of light element formation; derivation of percentage, by mass, of Helium; introduction to observational tests; contrasting decoupling and nucleosynthesis.
  • Inflation: definition; three problems (what they are and how they can be solved); estimation of expansion during Inflation; contrasting early time and current inflationary epochs; introduction to cosmological constant problem and quintessence.
  • Initial Singularity: definition and implications.
  • Connection to General Relativity: brief introduction to Einstein equations and their relation to the Friedmann equation.
  • Cosmological Distance Scales: proper, luminosity, angular distances; connection to observables.
  • Structures in the Universe: CMB anisotropies; galaxy clustering
  • Constraining Cosmology: connection to CMB, large scale structure (inc BAO and weak lensing) and supernovae.

Module learning outcomes

  • Be able to derive the equations describing the expansion of the Universe, and find its predicted expansion rate for a variety of circumstances.
  • Understand the evidence supporting key elements of the Concordance Cosmology model (including for Dark Energy and Inflation).