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

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

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.

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…

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

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.

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

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…

What is the connection between materials with weak and strong gravitational interactions?

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.

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.

Promotor: Koen Kuijken Co-promotor: Henk Hoekstra

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.

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

Promotor: Prof.dr. S. Portegies Zwart

What are the 'dark' components of the universe?

Promotie

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.

Promotores: Prof.dr. C.U. Keller, Prof.dr. H.C. Gerritsen

Leiden has a strong tradition in theoretical physics, thoroughly linked with experimental disciplines.

My work is motivated by the necessity to extend Standard Model of Particle Physics in order to explain three observed phenomena that this great theory fails to accommodate

Promotie

Promotie

Valérie Pattyn, Assistant Professor at Leiden University, researched

These are the proposed research projects for LEAPS 2019. Please note that not all projects will go ahead and some may still be added in the near future. Final funding decisions lie with the Faculty sponsors. And please make a note that if you are interested in an ESA project, to check if your state…

Leiden Observatory is going to use a new technique to carry out calculations on gravitational lensing measurements. They will do this is the context of research into the formation of elliptical galaxies. Alessandro Sonnenfeld (University of Tokyo) who developed this technique joined the research team…

Video interview with Subodh Patil, the new assistant professor in Theoretical Cosmology, about the gravitational waves, hidden universes, music, and whether Dutch, Danish and German fit into one brain.

Within the two-year Astronomy master’s programme, you can choose from seven specialisations, ranging from fundamental or applied astronomy research in cosmology, instrumentation or data science, to combinations of astronomy research with education, management or science communication.

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.

Researchers at Leiden Observatory study the fundamental physics that creates structure in the Universe. These processes collect matter into galaxies and gas into stars. With the use of powerful telescopes and advanced calculations and computer simulations, Leiden astronomers seek to understand the origin,…

Researchers at Leiden Observatory study the fundamental physics that creates structure in the Universe. These processes collect matter into galaxies and gas into stars. With the use of powerful telescopes and advanced calculations and computer simulations, Leiden astronomers seek to understand the origin,…

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.

New results from the Kilo-Degree Survey (KiDS) show that the Universe is almost 10 percent more homogeneous than previously thought. The new KiDS map was created using the partly Dutch OmegaCAM on ESO's VLT Survey Telescope on Cerro Paranal in Northern Chile. An international team of astronomers from,…

The European Space Agency (ESA) has approved the proposal for gravitational wave detector LISA. The launch for the space detector is planned in 2034. ‘A dream that comes true,’ says astronomer Elena Maria Rossi.

Astronomer Henk Hoekstra has been appointed Professor Observational Cosmology at the Leiden Observatory with effect from 1 August.

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.

Researchers Karène Sanchez and Sary Zananiri tell us about their research project CrossRoads, which investigates Christian communities during British Mandate Palestine (1918-1948) through cultural and linguistic lenses. The project was awarded a VIDI grant by NWO in 2017.

The project Hybrid Intelligence receives 19 million euros from the Gravitation programme of the Dutch Research Council (NWO). The consortium consists of six Dutch universities and combines human and artificial intelligence, aiming to amplify human intelligence instead of replacing it. Leiden professors…

How can young people grow up successfully and contribute to the present and future society? The consortium that is researching this will receive 22 million euros within the scope of the Gravitation programme.

The project MiCRop receives 20.3 million euros from the Gravitation programme of the Dutch Research Council (NWO). MiCRop will unravel the microbial community around crops. This knowledge will help to develop more sustainable crops that require fewer fertilizers and pesticides. Leiden professors Jos…

Gravitation programme grant Co-applicants Bernet Elzinga en Andrea Evers are two of the captains of the six teams, all led by main applicant Anita Jansen, Maastricht University.

Lezing

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.

An international team of astronomers, including Professor Koen Kuijken, has published a series of online articles presenting the first results of a major search for dark matter. Never before have researchers been able to chart so precisely the characteristics of groups of galaxies and their dark matter.…

Leading scientists in the field of the ethics and philosophy of technology are currently revising time-honoured key philosophical concepts such as autonomy, justice and responsibility, as these concepts are being challenged as a result of new technological developments. They receive 17.9 million euros…

Congres/symposium

Cosmologists have many possible models for the Universe, of which only one can be true. A new flowchart will eliminate some of them when two specific Universe features are accurately measured. Publication in Physical Review D on 7 November.

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