Cosmology and Structure Formation

Foundations of modern cosmology: Friedmann-Robertson-Walker metric, Friedmann equations, expansion, early Universe, perturbative expansion around the homogeneous solution, cosmic microwave background radiation (CMB), acoustic oscillations, structure formation, power spectrum, impact of cosmic neutrino background and neutrino mass, origin of density perturbations and inflation

After successful completion of the module the students are able to:

• understand current questions of cosmology
• solve the Friedmann equation
• know the influence of Dark Matter, Dark Energy, and Neutrinos on anisotropies in the cosmic background radiation and structure formation
• to use theoretical tools to calculate the dynamics of the baryon photon Plasma in the early universe
• to calculate density fluctuations in different epochs (material dominated, radiation dominated) and on different scales.
• understand and apply theoretical descriptions (linearized Einstein equations, Boltzmann equations, Compton scattering)
• understand the processes that determine the observed temperature fluctuations in the cosmic background radiation (Sachs-Wolfe effect, Doppler, Integrated SW Effect)
• know indications of inflationary expansion in the early universe, theoretical description of scalar field models and the origin of th density fluctuations
• make quantitative predictions of inflation and to compere them with observations

No preconditions in addition to the requirements for the Master’s program in Physics. Knowledge of general relativity is helpful, but not compulsory.

The module consists of a lecture and an exercise class.

Starting from general physical principles (equations of motion derived from variation of an action, thermoynamics, Boltzmann-Equations) the physical processes that are relevant for cosmology will be discussed systematically in a comprehensible way in th electure. Also  examples, overview over modern questions and methods are given. The lecture is given mainly on blackboard.

In the exercise the learning content is deepened and exercised using problem examples and calculations. Thus the students are able to explain and apply the learned physics knowledge independently.

Presentation, blackboard, problem sheets

• S. Dodelson: Modern Cosmology, Academic Press, (2003)
• S. Weinberg: Gravitation and Cosmology, John Wiley & Sons, (1972)
• E.W. Kolb & M.S. Turner: The Early Universe, Westview Press, (1994)
• J. Lesgourgues & S. Pastor: Neutrino cosmology, Cambridge University Press, (2013)

There will be a written exam of 60 minutes duration. Therein the achievement of the competencies given in section learning outcome is tested exemplarily at least to the given cognition level using calculation problems and comprehension questions.

For example an assignment in the exam might be:

• Explanation of physical processes relevant for structure formation and the cosmic microwave background
• Impact of dark matter, dark energy, neutrinos on structure formation
• Impact of various cosmic parameters on the cosmic microwave background
• Evolution of density perturbations in various epochs, relevant scales and processes, theoretical description
• Hints for inflation, predictions, theoretical description
• Linearized Einstein and Boltzmann Equations, relevant processes, approximations
• reionization