Governments have increasing amounts of data at their disposal. How can big data be used in policymaking? And are governments ready to deal with all this data? That is what Sarah Giest, Assistant Professor at the Institute of Public Administration, is interested in.

Several techniques are explored for going beyond the born-oppenheimer static surface model for molecule-surface reactions.

Bringing together a globally representative team of scholars, this Handbook provides a comprehensive overview of comparative syntax, the study of universal and variable properties of the structure of building blocks in natural language.

The master’s specialisation Cosmology at Leiden University is positioned at the interface between Theoretical Physics and Observational Astronomy. The main elements are theory, data analysis and numerical simulations, with research on the origin of dark matter as one of the highlights.

This thesis is dedicated to the exploration of the primordial dark ages: unknown physics during the earliest stages of the Universe’s expansion that have not yet been directly probed by observations. Cosmic inflation is a burst of exponential expansion of space after the “Big Bang”.

Collecting as much information as possible about administering a new medicine to people can save a lot of money.

This omnibus brings together some old and some recent works by Jos Gommans on the warhorse and its impact on medieval and early modern state-formation in South Asia.

Nadine Raaphorst wrote an chapter for The Oxford Handbook of Administrative Justice about how two notions of fairness are studied in street-level bureaucracy literature and about the factors that influence how bureaucrats behave in this regard.

Bahar Şimşek defended her thesis on 4 May 2021.

On Wednesday 14 May 2025 Remzi Çakırlar successfully defended a doctoral thesis and graduated.

Public sector decision-makers operate amidst an abundance of information and unclear political objectives. Attention is the sine qua non of policy-making: What is attended to can be addressed in policy responses; what is overlooked or goes unnoticed cannot. Despite its importance, public administration…

A master's degree in Psychology at Leiden University combines theoretical knowledge with academic and professional skills, making you an attractive candidate for many employers. However, there are far more graduates than vacancies, especially in mental health care, and competition is therefore fierc…

A master's degree in Psychology at Leiden University combines theoretical knowledge with academic and professional skills, making you an attractive candidate for many employers.

LIACS prof. Grzegorz Rozenberg is one of the world leaders in research on Theoretical Computer Science and Natural Computing. He is often called the guru of Natural Computing.

LIACS prof. Grzegorz Rozenberg is one of the world leaders in research on Theoretical Computer Science and Natural Computing. He is often called the guru of Natural Computing.

The master's specialisation Clinical Neuropsychology consists of three main parts: the mandatory and elective courses, a thesis and an internship.

Theoretical physicist Stephen Hawking (76) passed away on 14 March at his home in Cambridge, having been a long-term sufferer of the muscular disease ALS. A number of Leiden scientists look back at the life and scientific career of this world-famous physicist. 'He was very approachable and extremely…

Edited by linguists Jenny Audring (Leiden University) and Francesca Masini (University of Bologna), this is a unique handbook with a focus on morphology theories rather than morphological data. It covers a wide array of morphological theories, from traditional twentieth century models to current theoretical…

The master’s specialisation Theoretical Physics consists of 120 European Credit Transfer System (EC) points and includes electives (60 EC) and two research programmes (30 EC each).

On May 31st, Bobby Ruijgrok succesfully defended his doctoral thesis and graduated. The Leiden University Centre for Linguistics congratulates Bobby on this great result.

Lecture

Historical Sociolinguistics is the study of the relationship between language and society in its historical dimension. This is the first textbook to introduce this vibrant field, based on examples and case studies taken from a variety of languages.

Not all problems are easy to solve, but with enough bright minds, you make progress step by step. ‘The kind of problems I am interested in have been occupying mathematicians for over two millennia,’ says theoretical mathematician David Lilienfeldt. In September, he started at the Mathematical Institute…

My PhD research is devoted to studies of the conjectural cluster-algebraic symmetry in the theory of topological string, which is the simplest, however already non-trivial sector in the theory of string.

Theorists have recently made substantial progress in simulating reactive molecule-metal surface scattering but still face major challenges. The grand challenge is to develop an approach that enables accurate predictive calculations of reactions involving electronically excited states with potential…

Find out how to apply for Research in Physics, theoretical at Leiden University by following our step-by-step guide.

Contact Theoretical Chemistry

An accurate description of reactive scattering of molecules on metal surfaces often requires the modeling of energy transfer between the molecule and the surface phonons. Although ab initio molecular dynamics (AIMD) can describe this energy transfer, AIMD is at present untractable for reactions with…

A story of Two Mosuls, The Resurrection of the Iraqi Armed Forces and the military defeat of ISIS. In this article, published in the Journal of Strategic Studies, the authors Maarten Broekhof, Martijn Kitzen and Frans Osinga discuss the military adaptation by the Iraqi armed forces and their role in…

Explore the MSc in Political Theory: Legitimacy and Justice at Leiden University. Dive into core themes like justice and legitimacy, study classical and modern political theory, and sharpen your analytical and philosophical skills.

The bi-annual interactive seminars of the Platform for Postcolonial Readings are all about sharing our enthusiasm about our field of research and our eagerness to learn more about its theoretical intricacies. Our seminars, although informal, adopt a well-defined format. Each meeting is organized around…

The programme will give you the opportunity to choose from a broad range of topics to study. You will be part of an international multidisciplinary research team at the LION.

Graphene, the ultra-thin wonder material just a single carbon atom in thickness, holds the promise of such impressive applications as wear-resistant, friction-free coatings. But first manufacturers have to be able to produce large sheets of graphene under precisely controlled conditions. Dirk van Baarle…

PhD candidate Ludwig Hoffmann will spend two years at Harvard University in the US thanks to a Rubicon grant he won on April 11. Using theoretical models he studies biological tissues, for example during morphogenesis. This is the process that causes tissue or organisms to develop their shape. ‘This…

We are living through an age in which social media platforms have given way to entirely new forms of politics and politicking. It is no exaggeration to say: there is a before and after social media.

Jochem van den Boogert defended his thesis on 18 November 2015

Big data promises to transform public decision-making for the better by making it more responsive to actual needs and policy effects. However, much recent work on big data in public decision-making assumes a rational view of decision-making, which has been much criticized in the public administration…

Physicists at the Leiden Institute of Physics (LION) conduct fundamental research into physical phenomena. They are inspired by curiosity and the desire to know more about the world in which we live. This research has always paved the way for new practical applications. These are something that the…

Much of the work of Serge Fehr, Professor of Quantum Information Theory, is abstract and theoretical and comprehensible to very few people. But his work helps make the digital world safer so that in future our internet banking will still be problem free, for instance. He will explain more in his inaugural…

Our group operates at the cross-roads of different disciplines: molecular and cellular microbiology, biochemistry, structural biology and biophysics. The group harbors expertise in a multitude of molecular and cellular approaches including:

This book brings together phonologists working in different areas to explore key questions relating to phonological primitives, the basic building blocks that are at the heart of phonological structure and over which phonological computations are carried out.

This article discusses the impact of symbolic gender representation on the willingness of citizens to coproduce.

It has been a long-standing mystery how complex biological structures emerge from such seemingly uncoordinated building blocks as cells and tissues, in the presence of only minimal environmental guidance.