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

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.

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.

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.

Overkleeft

Promotor: T. H. Oosterkamp

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.

The aim of this project was to estimate emissions from lead products-in-use for the past, the present and the future and assess the development of toxicological risks associated with these products.

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.

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…

Nieuw onderzoek van de National University of Singapore en Leiden laat zien dat chimpansees en bonobo’s net zoveel contrast in hun ogen hebben als mensen, waardoor ze gemakkelijk de richting van iemands blik kunnen volgen.

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

Promotor: Koen Kuijken Co-promotor: Henk Hoekstra

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.

Negentig jonge, pas gepromoveerde wetenschappers kunnen vanaf 1 februari reageren op een postdoc-positie binnen het LEaDing Fellows Postdocs Programma.

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.

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

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

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

Valetudo, zo hebben de astronomen het nieuw ontdekte Jupitermaantje genoemd. Het is een weerbarstig exemplaar dat dwars tegen haar soortgenoten in beweegt. In de Volkskrant reageert Leidse astronoom Simon Portegies Zwart op de bijzondere ontdekking.

Prof. Vriesendorp en prof. Wessels zijn opgenomen in de 2020 Lawdragon 500 Leading Global Restructuring & Insolvency Lawyers. Prof. Haentjens is genoemd in de 2020 Lawdragon Leading Global Restructuring Advisors & Consultants.

De president van Indonesië, Susilo Bambang Yudhoyono heeft Jan Slikkerveer, hoogleraar Etnobotanische Kennissytemen in Ontwikkelingslanden, persoonlijk uitgenodigd om een lezing te houden op het World Culture Forum. Dat wordt van 24 tot 27 november in Indonesië gehouden.

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…

Lezing, Studium Generale

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”.

Dit team zorgt ervoor dat alle Una Europa activiteiten soepel verlopen en biedt ondersteuning aan Leidse collega's die direct betrokken zijn bij Una Europa activiteiten.

The focus of the dissertation

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-…

There are many interpretations of quantum mechanics, and ultimately experiments are needed to verify or falsify these interpretations.

Promotor: Jelle S. Kaastra Co-promotor: Jelle de Plaa

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

De meeste materie in het heelal is onzichtbaar, vermoeden veel astronomen. Maar hoe weeg je donkere materie die je niet kunt zien? Hoogleraar Henk Hoekstra zoekt naar een oplossing. Oratie op 25 juni.

Invasive lobular carcinoma (ILC) is the second most common type of breast cancer.

Cardiovascular disease is the leading cause of death worldwide.

Promotor: A. Doelman, Co-promotor: J.D.M. Rademacher

Antibiotic resistance, caused by widespread use of antibiotics, leads to bacterial infections that are difficult, if not impossible, to treat and is a major worldwide health concern.

Geometric phases lead to a nontrivial interference result when an electron's different quantum mechanical paths choices encircle a magnetic coil in an Aharonov-Bohm experiment.

An objective of this research was to achieve direct, well-defined and non-rate-limiting electron transfer between respiratory enzymes and the electrode surface by means of 'Q-wires'.

Sphingolipids are important membrane compounds with a variety of functions. In mammalian cells, different enzymes are involved in the metabolism of sphingolipids, but interruption of this metabolism process leads to different diseases.

This Thesis shows discoveries in non-linear astrochemical kinetics as well as a deeper analysis of dark clouds chemistry.

In previous studies at our laboratory it was demonstrated that drug exposure of HepG2 cells can lead to an altered TNFα-induced NF-κB oscillatory phenotype, concurrent with a synergistically increased sensitivity for TNFα-induced apoptosis.

Promotoren: Prof.dr. G.R. de Snoo en Dr. R. Heijungs

Promotor: C.A.J. Knibbe, Co-promotor: J.J. Boelens, R.G.M. Bredius

Promotor: P.G.L. Klinkhamer, Co-Promotores: K. Vrieling, P.P.J. Mulder

The four possible segments A, T, C and G that link together to form DNA molecules, and with their ordering encode genetic information, are not only different in name, but also in their physical and chemical properties.

Single-molecule spectroscopy has become a powerful method for using organic fluorescent molecules in numerous applications.