The first direct detection of gravitational waves opened the possibility of mapping the Universe via this new and independent messenger.

Promotor: K. Kuijken, Co-Promotor: H. Hoekstra

One of the most important correlation functions in physics, especially in cosmology, is the energy density, which describes how much energy is present at each point in spacetime due to matter fields. A key contribution to the energy density of the primordial universe comes from gravitational waves (GWs),…

We explored the Universe using weak gravitational lensing, a phenomenon that occurs when light from distant galaxies is bent by the gravitational fields of closer cosmic objects, much like how a lens distorts light.

Of all the mass in our Universe, 80% is thought to consist of a hypothetical and invisible substance called dark matter (DM).

In this work, I explore the creation of new methods that optimize simulations of the gravitational N-body problem. Specifically, I take advantage of the recent popularity of Machine Learning methods to find tools that can suit this problem.

In astronomy, the interpration of observations and measurements plays a crucial role: we rely purely and fundamentally on the information that reaches us as observers. And 80% of all matter in the universe is undetectable directly.

Promotor: Prof.dr. S. Portegies Zwart

In this thesis we study the landscape of gravitational models which modify GR by introducing an additional scalar degree of freedom (d.o.f.) to source Cosmic Acceleration.

Promotor: Prof.dr. J. Schaye, Co-promotor: Marcello Cacciato

At the largest scales, two ingredients dictate the distribution of matter in the Universe. The first is dark matter, acting as an invisible scaffolding held together by gravitational forces.

It's one of the big cosmology debates: the universe is expanding, but how fast exactly? Two available measurements yield different results. Leiden physicist David Harvey adapted an independent third measurement method, using the light warping properties of galaxies predicted by Einstein. He published…

This thesis investigates the structural evolution and assembly of galaxies since the first few billions years after the big bang.

Three major research projects involving Leiden scientists have been awarded a grant from NWO’s Gravitation Programme. The projects are on innovation processes, organs-on-chips and quantum software.

Leiden University is involved in five new NWO Gravitation projects. Two relate to mental disorder and the remaining three to a healthy lifestyle, the combination of human and artificial intelligence, and the special relationship between plants and microbes.

The physical origin of the dozens of stellar-mass binaries, the mergers of which have been detected by the LIGO-Virgo-KAGRA collaboration via gravitational waves, is still unknown.

The ultimate goal of cosmologists is to find a cosmological model able to explain the current observational data.

For centuries astronomers studied the Universe by collecting light. Nowadays, we are living in times of great technological advancements, which allow us to explore our Universe in a new way - though gravitational wave radiation.

The Advanced Nano-electrochemistry Institute Of the Netherlands (ANION) consortium will receive 23.6m euros in Gravitation funding for research on important electrochemical processes for energy transition. An additional four consortia with members from Leiden have also been awarded funding.

Galaxy intrinsic alignments induce a major astrophysical contamination to weak gravitational lensing measurements and need to be modelled and mitigated when extracting cosmological information from such measurements.

Promotor: Koen Kuijken Co-promotor: Henk Hoekstra

Een knelpunt bij burgerinitiatieven is dat de wet voor initiatiefnemers vaak een barrière vormt. Esmee Driessen, gastdocent Staats- en bestuursrecht en expert in burgerparticipatie, bespreekt twee belangrijke verbeterpunten uit haar proefschrift, waarop zij in juni 2024 promoveerde, in OverheidvanNu…

Geheime diensten en criminelen kunnen inbreken in slimme apparaten, door slechte beveiliging. De markt lost het niet op: bedrijven willen gadgets verkopen, burgers doen ook weinig. NRC sprak hierover met Bibi van den Berg.

Galaxies form and live inside dark matter haloes. As a consequence, they are exposed to the tidal fields generated by the surrounding matter distribution: this imprints a preferential direction to the galaxy shapes, which leads to a coherent alignment on physically close galaxies, called intrinsic a…

In this thesis, the research focuses on the properties of dark matter and dark matter haloes and how they connect with the galaxies we can observe in the Universe.

Professor Frank den Hollander has been awarded a 10-year grant through the NWO Gravitation program, jointly with colleagues from the University of Amsterdam, the Center for Mathematics and Computer Science in Amsterdam, and the Technical University of Eindhoven.

Three major cosmology-focused missions are planned for the next decade: the Euclid space telescope, the Vera C. Rubin Observatory in Chile, and the Nancy Grace Roman Space Telescope.

Many astronomers suspect that most of the matter in the universe is invisible. So how can you weigh dark matter if you can't actually see it? Professor Henk Hoekstra is looking for a solution. Inaugural lecture 25 June.

Voor zowel archeologen, paleontologen en geologen als vrijwilligers in de archeologie en paleontologie is het geen verrassing meer dat op de stranden van de Nederlandse kust fraaie vondsten gedaan kunnen worden. Vele artikelen, boeken, tentoonstellingen, congressen, lezingen, ‘zoekdagen’, krantenberichten,…

Dit proefschrift beschrijft een collectie aan alternatieve strategieën voor het begrijpen, ontwerpen en toepassen van lipide nanosystemen, waarin de rol van de bio-nano interacties centraal staan. In het bijzonder wordt gekeken naar de interactie van RNA-lipide nanosystemen, bekend van de toepassing…

Wat zijn de huidige energiekosten en hoe is de comfortbeleving het wooncomfort in een bepaalde groep huurders van woningcorporatie Portaal?

Op deze pagina vind je antwoorden op veelgestelde vragen.

Our research primarily focuses on the early universe and its origins in theories that go beyond the Standard Model of particle physics.

Hoe kan de City Deal Kennis Maken bijdragen aan het formuleren van maatschappelijk relevant onderzoek dat de stad in al haar diversiteit centraal stelt? In de stad Leiden zijn burgers momenteel maar in beperkte mate betrokken bij het bepalen van de agenda van de lokale City Deal Kennis Maken. Dit onderzoeksproject…

Vandaag de dag liggen statistische methodes aan de grondslag van beslissingen in allerlei facetten van het leven, van de gezondheidszorg en agricultuur tot de financiële sector en marketing.

Leraar worden in het voortgezet onderwijs? Bekijk dan deze video.

Foute taal? Bestaat niet!

What physics controls the properties of quantum matter, such as how electrons flow inside high-temperature superconductors? This question has captivated the physics community and industry for decades, in part due to the great technological potential such materials have, but also because they have resisted…

Welcome to the Hensen Lab! We are a young dynamic experimental research group starting at the Leiden Institute of Physics. Our lab addresses one of the key challenges of modern physics: understanding the interface between quantum mechanics and general relativity.

De positie van kunst en kunstenaars in de westerse samenleving

On the 3rd of April, Sebastiaan van der Lubben successfully defended a doctoral thesis. The Leiden University Centre for Linguistics congratulates Sebastiaan on this achievement!

Het CPL biedt opleidingen voor hogeropgeleide professionals: starters, ervaren professionals en leidinggevenden.

Improvements of weak gravitational lensing shape measurements are presented and some used for data analysis.

Kyra van der Moezel defended her thesis on 7 September 2016.

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”.

Met AI kunnen nieuwsredacties razendsnel beelden genereren — maar tegen welke prijs? Dit onderzoeksrapport opgesteld door prof. dr. Jaap de Jong, dr. Astrid Vandendaele, Maartje van der Woude en Stef Arends (Universiteit Leiden), baseert zich op 59 interviews met beeldmakers, redacteurs en experts uit…

The CNaVT exam is the official, international exam of Dutch as a Foreign Language for all who learn Dutch all over the world. The Catholic University of Leuven organizes the exam. The Dutch Language Union has commissioned this collaboration.