# Cosmology (900F3)

15 credits, Level 7 (Masters)

Autumn teaching

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.

### Teaching and assessment

We’re currently reviewing teaching and assessment of our modules in light of the COVID-19 situation. We’ll publish the latest information as soon as possible.