MPs in the Netherlands are first and foremost motivated by their direct environment, i.e. the parliamentary and partisan institutions.

The gripping story of a collective passion for freedom that shook the world.

Nikoleta Yordanova, a political scientist at Leiden University, will lead an international research consortium funded by the European NORFACE Network to complete a multi-disciplinary project ‘Willingness and Capacity for EU Policy Action in Turbulent Times: Conflicts, Positions and Outcomes’ (EUINACTION).…

This NWO-funded research programme focuses on the assumptions and methodology of the writing of history of science. History of science is in many respects a flourishing discipline: it currently yields an impressive volume of studies. Systematic reflection about the ways in which history of science may…

Leiden University and the city of The Hague are working closely together to increase the impact of our research and education in order to contribute as much as possible to the development of the city.

The starting hypothesis of the project is that secrecy is not always inimical to democratic governance as conventional wisdom has it.

Mass, time, space, and complexity — physicists in Leiden are launching eight new research projects tackling some of the most fundamental themes in quantum mechanics. Their goal: to push the limits of current quantum theories.

Chaider Bamualim defended his thesis on 9 September 2015

This thesis explores Breaking of Ensemble Equivalence (BEE) in random graph models by examining the spectral properties of adjacency matrices. The goal is to identify spectral characteristics that differentiate random graph ensembles, enhancing the understanding of complex network structures and beh…

On Tuesday 30 September 2025, PhD candidate Kathleen Brown will defend her dissertation 'Deception, Risk, and Evasion: The Politics of Sovereign Debt in Emerging Markets' in Leiden’s Academy Building. Her research sheds light on the hidden world of sovereign debt politics, revealing how governments…

No evidence found that increasing migration leads to an increase in politically and ideologically motivated criminality. Migration flows have, however resulted in increased polarisation in the Netherlands.

The aim of this study is to further develop the Open Science Monitor, which started as a pilot study.

Why did India develop a strong military partnership with the state of Irael, after having ignored it for 42 years? How could both countries develop defense ties in spite of limited political leadership involvement? Finally, what are the prospects for defense relations as India grows to become one of…

Political scientist Corinna Jentzsch (Leiden University) explains why Mozambique is not (yet) a success story.

The research programme Statistical Science is concerned with the analysis and interpretation of masses of data, the quantification of uncertainty using probability models, and the development and benchmarking of algorithms and methods with these aims.

Mr. Ade Jaya Suryani defended his thesis on 28 January 2021

Who tried to influence the mission and position of the Dutch security services between 1912 and 1992, what effect did that have on the form and contents of the security services? How to account for transformations of the security services?

Citizens’s attitudes towards trade are not only about the (perceived) economic effect. Commerce also has a variety of security implications. Employing an original experiment, political scientists Matthew DiGiuseppe (Leiden University) and Katja Kleinberg (Binghamton University) demonstrate that security…

In September 2021, ACPA PhD Candidate Gabriel Paiuk will premiere a new work titled Sound Theory (The Clouds) as part of the 2021 Gaudeamus Muziekweek Festival. The performance will take place on September 10th, 20:30 at the De Helling (Utrecht, NL).

Promotor: P. Stevenhagen, Co-promotor: R.M. van Luijk

In this article, Jasmijn Boeken, explores in which ways the defining characteristics of the different zones can be found in the digital sphere.

Populist opposition parties are less likely to engage in policy-making behaviour (participating in or directly influencing legislative production) and somewhat more likely to engage in scrutiny behaviour (monitoring and criticising government actions).

Political Scientist Gisela Hirschmann (Leiden University) asks how international organisations can be compelled to comply with respect human rights. She finds that this is done through ‘pluralist accountability’: external third parties such as courts, NGOs, or regional organisations holding international…

Citizens in multiple crime-ridden countries strongly support the militarization of security—that is, placing the military in charge of traditional policing duties. Yet, we know little about the determinants of such support. Do people approve of militarization even in the face of human fatalities? Political…

In theory, states can gain security by acquiring internal arms or external allies. Yet the empirical literature offers mixed findings: some studies find arms and allies to be substitutes, while others find them to be complements. Political scientists Matthew Digiuseppe (Leiden University) and Paul Poast…

A comparative analysis of legitimation strategies in tree hybrid regimes: Russia, Venezuela, and Seychelles.

The goal of this book is to place architectural studies, in which people’s interactions with each other and material resources are key, at the crossing of both landscape studies and material culture studies, where it belongs.

There are eight institutes at the Faculty of Mathematics and Natural Sciences:

Alumnus Stan van Haasteren went to Northern Ireland in 1995 as a freelance journalist with a guitar strapped to his back and recently wrote a book about his experiences in Belfast. ‘The big difference with then is that today there is no more violence. But it's still a divided city.’

Leiden Professor of Number Theory Manjul Bhargava has been awarded a Fields Medal, widely regarded as the Nobel Prize for Maths. Bhargava is a professor in Princeton, and since 2010 has also been the holder of the Stieltjes chair in Leiden.

As one of the most influential ideas in modern European history, democracy has fundamentally reshaped not only the landscape of governance, but also social and political thought throughout the world.

This thesis explores Breaking of Ensemble Equivalence (BEE) in random graph models by examining the spectral properties of adjacency matrices. The goal is to identify spectral characteristics that differentiate random graph ensembles, enhancing the understanding of complex network structures and beh…

The Faculty of Science

Festival

What is the origin of educational ideas, e.g., the idea that intervention in infancy has long-lasting effects on development.

Robert Pee, William Michael Schmidli (Eds.) This book posits that democracy promotion played a key role in the Reagan administration’s Cold War foreign policy.

Conspiracy theories are of all times, and the government should never dismiss them as a fantasy of fools. Certainly not now, when it turned out that authorities made a conspiracy themselves with a journalist threatened with murder. Which proves that the truth is always more insane than you could have…