The radio sky harbours both galactic and extragalactic sources of arcminute- to degree-scale emission of various physical origins. To discover extragalactic diffuse emission in the Cosmic Web beyond galaxy clusters, one must image low–surface brightness structures amidst a sea of brighter compact fore-…

Promotor: Prof.dr. B.R. Katzy, Prof.dr. J. de Vries

I have studied the hot, diffuse gas around and between galaxies. Specifically, I have used the EAGLE numerical simulations of galaxy formation to predict the properties of this gas, and I have used those properties to predict specific observables: soft X-ray absorption and emission lines.

Understanding the formation and evolution of planetary systems is one of the most fundamental challenges in astronomy. To directly image and study young exoplanets and the circumstellar disks they form from, dedicated high-contrast imaging instruments are built.

Tomography is a powerful technique to non-destructively determine the interior structure of an object.Usually, a series of projection images (e.g.\ X-ray images) is acquired from a range of different positions.

Promotor: R. Tijdeman, Co-promotor: H.J.J. te Riele

Promotor: Prof.dr. P.G.L Klinkhamer, Co-promotor: K. Vrieling

Promotor: E. Bouwman, Co-Promotor: S. Bonnet

Producing green energy has become the main goal in our society in the search of reducing or eliminating the carbon emission from fossil fuels.

When observing star-forming galaxies, we are not only seeing stellar light, but we also see how this interacts with galactic gas and dust. This thesis contains studies of the stellar, nebular and dust properties of low mass star-forming galaxies.

Real-life processes are characterized by dynamics involving time. Examples are walking, sleeping, disease progress in medical treatment, and events in a workflow.

Promotor: Prof.dr. L.J. Slikkerveer

The field of exoplanet research is rapidly advancing through the development of new technology, observing techniques, and post-processing methods.

Self-assembly is an abundant process in nature and is vital to many processes in living organisms.

This thesis explores the theoretical and observational properties of distant massive galaxies that harbour active black holes in their centres and shine brightly at radio wavelengths.

Optimization tasks in practice have multifaceted challenges as they are often black box, subject to multiple equality and inequality constraints and expensive to evaluate.

Why do black holes emit thermal radiation? And how does a closed quantum system thermalize?

The main research question of this thesis was: Can nitrogen cycling on dairy farms on peat soil in the Dutch Green Heart area be improved by adapting management to the nitrogen supply from soil and by using other grassland species and crops without affecting milk production?

In this thesis we will explore the use of fuzzy systems theory for applications in bioinformatics.

Promotor: H.J. van den Herik, B.R. Katzy, Co-promotor: K. Sailer

The high velocity tail of the total velocity distribution of stars provides essential insight into fundamental properties of the Galaxy.

Electron microscopy has become an extremely important techniquein a wide variety of elds.

A dense region of a gaseous and dusty cloud collapses to form a protostar surrounded by a disk and an envelope. This thesis uses both observations and models to study physical and chemical conditions of these protostellar systems which are likely where planets start to form.

Lezing, Tuesday Talks: Science Insights

Zoals gebruikelijk doet de Universiteit Leiden mee aan de viering van Leidens Ontzet, ook nu het programma op 2 en 3 oktober virtueel is. Kijk naar de talkshow over intrigerende wetenschap en volg het gesprek en de historische lezing over de Leidse Pilgrimgeschiedenis. Samen thuis, samen uit!

Lezing

Kunst en vrije tijd, Kunst en vrije tijd

Joris van den Tol, docent International Studies, heeft een NWO Rubiconbeurs gekregen om twee jaar lang onderzoek te doen aan Harvard University (Verenigde Staten). Hij zal onderzoeken hoe 17e-eeuwse Nederlandse handelaren en Engelse plantagehouders samenwerkten in een trans-Atlantische lobbyallianti…

This research project studies the distribution and impact of medieval malaria in the Netherlands.

Op donderdag 23 april ontvingen bijna 400 leerlingen uit 5 vwo hun certificaat tijdens de feestelijke slotbijeenkomst van LAPP-Top. De LAPP-Top deelnemers doken acht weken lang één keer per week de collegezaal in om één van de achttien aangeboden LAPP-Top programma’s te volgen. De presentaties van de…

De titel van de lezing is ‘On the Emergence of Space and Gravity’, de lezing is openbaar, Engelstalig en duurt speciaal voor deze gelegenheid een half uur, i.p.v. van het gebruikelijke kwartier voor de This Week’s Discoveries lezingen.

Met ingang van 1 november 2025 is universitair hoofddocent Ethics and Digital Technologies Francien Dechesne benoemd tot bijzonder hoogleraar ‘Data and AI for the Rule of Law’ aan de Tilburg School of Humanities and Digital Sciences van Tilburg University.

Bas van Opheusden, student theoretisch natuurkunde, is de winnaar van de Janneke Fruin-Helb Beurs 2012. Van Opheusden schreef een voorstel voor een verblijf aan het gerenommeerde Amerikaanse onderzoeksinstituut Princeton University . Hij doet daar aan het institute for computational neuroscience een…

Bio-Farmaceutische Wetenschappen staat met een overall score van 89.9 op de 9e plaats wereldwijd, de 6e plaats binnen Europa en de 1e plaats in Nederland in de QS World University Rankings, een uitzonderlijke prestatie. Dit blijkt uit de lijst die onderwijsadviesbureau QS publiceerde.

Kiemproject: Hoe kunnen metaforen bijdragen aan betere maatschappelijke betrokkenheid bij quantumwetenschap en -technologie, en welke factoren beïnvloeden de acceptatie of weerstand tegen metaforen bij zowel experts als leken?

The research in this dissertation aims to optimise blood donation processes in the framework of the Dutch national blood bank Sanquin. The primary health risk for blood donors is iron deficiency, which is evaluated based on donors' hemoglobin and ferritin levels.

How do you engage society to stop biodiversity loss? How do you create political and social involvement to deal with climate change? And how do you balance the economic needs of industry with the negative effects of pollution? If you find these kinds of questions interesting, then this Pre-University…

Onlangs is een Memorandum of Understanding (MOU) ondertekend tussen het Centrum voor Milieuwetenschappen (CML) - Universiteit Leiden en de Mulawarman universiteit in Samarinda, Kalimatan provincie, Indonesië. De MOU is van kracht gedurende een periode van vijf jaar en omvat de intentie om samen te werken…

In this thesis we study quantum transport phenomena on the nanometer scale, in two classes of materials: topological insulators with induced superconductivity and graphene superlattices.

Quantum computing is an emerging technology, which holds the potential to simulate complex quantum systems beyond the reach of classical numerical methods.Despite recent formidable advancements in quantum hardware, constructing a quantum computer capable of performing useful calculations remains challenging.In…

Heterogeneous catalyzed processes are highly significant to the chemical industry. Dissociative chemisorption (DC) of molecules on surfaces is always considered as a step with a high degree of rate control for heterogeneous catalysis.

Leiden University’s Academic Challenge

In this Ph.D. thesis we study the interaction of low energy electrons with thin materials, namely layered materials (graphene, hexagonal boron nitride, molybdenum disulfide) and organic films. At these low energies the quantum mechanical wavelength of the electron wave function is in the order of a…

Kunnen we van quantum-verrassingen quantum toepassingen maken? Kunnen we het leven onderzoeken en opbouwen vanuit de nano-schaal?

Promotores: Prof.dr. M. Franx, Prof.dr. M. Kriek (Univ. of California at Berkeley)

This multidisciplinary minor provides students with knowledge on how and why humans became the way they are. The minor focuses on the evolution of the species Homo sapiens from other hominin lineages and animal ancestors, and on the various factors shaping this process. Not only is human evolution of…

How were the Russians, under early modern conditions, able to incorporate this distant, undeveloped and, because frequent nomadic attacks, dangerous territory? And what role did the Kolyvan-Voskresensk plants play in this process?

This project uses archaeological, literary and epigraphic evidence to investigate urban development in Roman-period North Africa, compiling this in a GIS-linked database in order to analyse the development of urban settlement spatially over time.

Artin L-functions associated to continuous representations of the absolute Galois group G_K of a global field K capture a lot of information about G_K as well as arithmetic properties of K.