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Large Scale Structure and Galaxy Formation


Admission requirements

Familiarity with basic concepts of cosmology is assumed. The student is assumed to have basic knowledge of the thermal history of the universe, recombination, the cosmic microwave background, cosmic distances, horizons, and to be able to work with the Friedmann equation. In terms of the Leiden curriculum, the Astronomy master's course Origin and Evolution of the Universe provides the ideal preparation.


How galaxies and the large-scale structures in which they are embedded form is a fundamental question in extra-galactic astronomy. It is an area that has seen tremendous progress, but is still constantly challenged by ever-improving observational data. This course introduces you to this fascinating subject and the underlying physics, starting from how small density perturbations grow into dark matter haloes, to how baryons cool and form the galaxy population we observe today.

Physical concepts are derived from basic principles where possible. The emphasis is on intuitive rather than mathematically rigorous derivations.

Topics that will be covered include:

  • Statistical cosmological principle

  • Linear growth of density perturbations

  • Free streaming

  • Jeans smoothing

  • Radiation drag

  • The linear growth of potential fluctuations

  • The linear growth of peculiar velocities

  • Transfer functions and the matter power spectrum

  • Correlation functions

  • Redshift space distortions

  • The cosmic web

  • Non-linear spherical collapse

  • Scaling laws and virial relations

  • Halo mass functions and Press-Schechter theory

  • Biasing

  • Halo density profiles, shapes, and spins

  • The halo model

  • Semi-empirical models for galaxy clustering

  • Radiative cooling

  • Gas accretion

  • Angular momentum and galaxy sizes

  • Stellar and AGN feedback

  • Self-regulated galaxy formation

  • The epoch of reionization

  • The Gunn-Peterson effect and quasar absorbers

  • The thermal history of the intergalactic medium

Course objectives

Upon completion of this course you will be able to explain how (we think that) large-scale structures and galaxies form and evolve and you will be able to carry out calculations of the formation of structures in the universe.

Upon completion of the course you will be able to:

  • Understand the concepts covered in the course, including those listed above

  • Be able to explain the current picture of the origin and evolution of large-scale structure and galaxies

  • Make quantitative but approximate models for the evolution of large-scale structure, dark matter haloes, the circumgalactic medium, galaxies and the intergalactic medium

  • Understand the main limitations of the models and know some of the unanswered questions

  • Be able to read the literature and follow talks on the topics covered


See Astronomy master schedule

You will find the timetables for all courses and degree programmes of Leiden University in the tool MyTimetable (login). Any teaching activities that you have successfully registered for in MyStudyMap will automatically be displayed in MyTimeTable. Any timetables that you add manually, will be saved and automatically displayed the next time you sign in.

MyTimetable allows you to integrate your timetable with your calendar apps such as Outlook, Google Calendar, Apple Calendar and other calendar apps on your smartphone. Any timetable changes will be automatically synced with your calendar. If you wish, you can also receive an email notification of the change. You can turn notifications on in ‘Settings’ (after login).

For more information, watch the video or go to the 'help-page' in MyTimetable. Please note: Joint Degree students Leiden/Delft have to merge their two different timetables into one. This video explains how to do this.

Mode of instruction

  • Lectures

  • Exercise classes

Assessment method

  • Written exam (75%)

  • Four homework assignments: 25% (if higher than the result of the written exam)

Reading list

Lecture notes


As a student, you are responsible for registering on time, i.e. 14 days before the start of the course. This can be done via Mystudymap. You do this twice a year: once for the courses you want to take in semester 1 and once for the courses you want to take in semester 2. Please note: late registration is not possible.

Registration for courses in the first semester is possible from July; registration for courses in the second semester is possible from December. First-year bachelor students are registered for semester 1 by the faculty student administration; they do not have to do this themselves. For more information, see this page.

In addition, it is mandatory for all students, including first-year bachelor students, to register for exams. This can be done up to and including 10 calendar days prior to the exam or up to five calendar days in case of a retake exam. You cannot participate in the exam or retake without a valid registration in My Studymap.

Extensive FAQ's on MyStudymap can be found here.


Lecturer: Prof.dr. J. Schaye