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Complex Networks (BM)


Admission requirements

The course is open to third-year bachelor Mathematics, Physics and Astronomy students and first-year master students of all programs of Physics, Mathematics, Astronomy and Computer Science (including Bioinformatics, ICT&Business, Informatica&Economie).

The course assumes basic knowledge of physics, mathematics and computer science at the bachelor level. In particular, familiarity with elementary notions from calculus, probability theory and statistical physics are helpful. Some light computer programming will be involved as well.


Transportation, traffic, energy, communication and social networks form the backbone of modern society. In recent years, there has been a growing fascination with the complex “connectedness” that such networks provide. This connectedness manifests itself in many ways: in the rapid growth of the Internet and the World Wide Web, in the ease with which global communication takes place, in the speed at which news and information travels around the world, and in the spread of an epidemics or a financial crisis. These phenomena are based on the links that connect people and their decisions, and have global consequences. The course aims to provide students with a concise introduction into this lively area, and covers both theoretical principles and practical applications from a variety of different directions. Complex Networks is a multi-disciplinary course: it exposes views on Complex Networks from Physics, Mathematics and Computer Science, is aimed at students of and is taught by faculty from these disciplines.

Topics: * Real-world networks: concepts, properties, challenges; * Models: random graphs, preferential attachment, small worlds; * Maximum-entropy statistical ensembles of networks; * Network algorithms, visualization, simulation; * Percolation & epidemiology on networks; * Pattern detection on networks; * Computational complexity of processes on networks.

Course objectives

This course aims to provide an introduction to the field of complex networks, covering both theoretical principles and practical applications from different perspectives. Complex Networks is a multi-disciplinary course: it exposes views on the area from mathematics, physics and computer science, and is open to students from all programs in these three disciplines. At the same time it assumes basic knowledge at the bachelor level in each of these disciplines, including key concepts from calculus (differentiation, integration, limits), probability theory (probability distributions, random variables, stochastic processes), statistical physics (ensembles, entropy), and computer programming (C or Python). In terms of panorama, the course material is both challenging and rewarding. At the same time, it chooses a style of presentation that is tuned to a mixed audience, which inevitably means a breach with the styles that are commonly adopted in the three disciplines separately. As part of the learning goals of the course, the students should develop an interdisciplinary view to the study of Complex Networks. This is the reason why the course is taught by three instructors with different background. Each lecture (and the associated homework) takes a viewpoint from either Mathematics, Physics, or Computer Science. To further strengthen interdisciplinarity, students are asked to form mixed teams for doing the homework together.


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 sucessfully 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 the 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

See Brightspace

Assessment method

  • written examination (70%)

  • weekly assignments (30%)

The teachers will inform the students how the inspection of and follow-up discussion of the exams will take place.

Reading list

  • Course Notes/Diktaat (provided)


From the academic year 2022-2023 on every student has to register for courses with the new enrollment tool MyStudyMap. There are two registration periods per year: registration for the fall semester opens in July and registration for the spring semester opens in December. Please see this page for more information.

Please note that it is compulsory to both preregister and confirm your participation for every exam and retake. Not being registered for a course means that you are not allowed to participate in the final exam of the course. Confirming your exam participation is possible until ten days before the exam.

Extensive FAQ's on MyStudymap can be found here.


Prof. Diego Garlaschelli Dr. Rajat Hazra Dr. Akrati Saxena


Transferable skills: scientific curiousity, creating connections among different contexts and disciplines, thinking out of the box, being able to formulate hypotheses about problems for which one has no prior knowledge, abstraction and generalization in a multidisciplinary context.