The Mesoamerican research group 'Time in Intercultural Context: the indigenous calendars of Mexico and Guatemala' funded by the ERC and directed by prof. dr. Maarten Jansen, met up in Mexico from the 13th until the 23rd of February for a field seminar in the states of Tlaxcala and Hidalgo.

Twenty years from now, the world population is estimated to be around 9 billion people (now 8 billion). In combination with the improvements in living standards and the corresponding growth in consumption, this population will result in an enormous increase in the demand for food, consumables, water…

By carrying out fundamental research and providing excellent education, universities become a breeding ground for innovation and entrepreneurship.

From interpreting in Arabic and a visit to the dentist to a game of hockey. The temporary reception of 123 refugees in the University Sport Centre is running smoothly thanks to the enormous support from staff and volunteers. ‘It’s the children who most need attention.’

Sustainable energy from wind and solar is most readily available near the sea.

Promotor: Prof.dr. S.F. Portegies Zwart, Co-promotor: D.C. Heggie

Hot astrophysical plasma is ubiquitous in the Universe, from comets in our Solar system to the largest scale structures -- the cosmic web filaments. These hot plasmas, with the temperature of a few millions of degrees, are often observed in the X-ray wavelength range.

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

Until the 1990s, the only known planets were those in our Solar System. Three decades later, several thousand exoplanets have been discovered orbiting stars other than the Sun, and substantial efforts have been made to explore these strange new worlds through spectroscopic analyses of their atmosphe…

Inspired by natural photosynthesis, perovskite-based photoelectrochemical (PEC) systems are being developed for artificial photosynthesis, aiming to enhance solar-to-hydrogen conversion for green energy.

Twenty years from now, the world population is estimated to be around 8.7 billion people, compared to the current 7.3 billion. In combination with the improvements in living standards and the corresponding growth in consumption, this will result in an enormous increase in the demand for food, consumables,…

This thesis describes the development and validation of new high-contrast imaging techniques, with the ultimate goal of enabling the next generation of instruments for ELT-class telescopes to directly image Earth-like extra-solar planets orbiting around nearby stars.

Solar energy is used by photosynthetic organisms to drive energy required cellular processes. Is absorbed by two groups of pigments, located in the LHCs.

One of the key discoveries in exoplanet research over the past decade is the abundance of small planets in our Milky Way. Despite their high numbers, our understanding of their atmospheres remains limited, and it is unknown if they possess atmospheres at all.

Solar energy harnessed by plants and algae has great potential to be converted into biofuels for future generations.

Research in the Lars Jeuken group focusses on redox-active proteins and membranes enzymes, aiming to understand bacterial respiration at the molecular level for the development of antimicrobials and semi-artificial photo-synthetic cells.

The long-held desire - to link structure directly to function and to explain molecular mechanisms based on basic chemical or physical principles - is finally coming closer, satisfying not only our scientific curiosity but also offering new solutions to the many challenges in the field of health, energy…

This thesis is about the study of hydrocarbons via infrared spectroscopy.

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.

Promotor: P.J.J. Hooykaas, Co-Promotor: E.J. van der Zaal

To address the fundamental questions of how life on Earth emerged and how common life may be in the Universe, it is crucial to know the chemical composition of the planet-forming material.

Promotor: E. F. van Dishoeck, Co-promotor: C. Walsh

High-angular-resolution observations of the circumstellar material have uncovered numerous and very diverse substructures in protoplanetary discs, raising the question of whether they are caused by forming planets or other mechanisms.

The work done during this PhD research, aims to investigate the effect of tidal heatingin the observability of extra-solar satellites around exoplanets.

Large areas of space are filled by molecular clouds that consist of gas and dust grains that are the remnants of dead stars. When these clouds start collapsing, the decreasing temperature and increasing density cause gas particles to start accreting onto dust grain surfaces.

Astronomy began by studying the light from the stars. These stars are born in vast clouds of gas and dust.

Promotor: Prof.dr. H. J. A. Röttgering, Co-Promotor: Dr. M. Haverkorn

In this thesis, classes of strongly interacting quantum field theories, have been studied.

Matthew Fields, from Philadelphia, US, came to Leiden to study astronomy as part of the Euroscholars scheme. 'I came here to gain valuable research experience, and I haven't been disappointed!'

Prof. dr. Marcel Cobussen has published a free e-pub: The Field of Musical Improvisation.

Dusted off and fresh from the field, some insight perspectives on the 2012 field season of the Proyecto Arqueologico Centro de Nicaragua. It's safe to summarize the field campaign as having generated some insights, and possible answers, many more contacts, and the occasional frustration for added bo…

The Robben Island field school in January and February 2011 investigated and documented the tangible and intangible heritage of Robben Island, encompassing the remains associated with various political prisoners, the Muslim exiles, the lepers and lunatics, the WWII soldiers and Navy personnel, the prison…

Research of the Leiden Institute of Chemistry into the development of a sustainable fuel cell has accidentally resulted in an exceptionally efficient catalyst for the production of hydrogen peroxide. The catalyst, discovered by Dennis Hetterscheid and PhD candidate Michiel Langerman, may lead to a more…

His dissertation has been completed for more than a year, but due to corona the defence had been postponed. On Wednesday 30 September, Machiel van der Heijden will finally be able to defend his dissertation Transnational Networks and Domestic Agencies: Making Sense of Globalizing Administrative Patterns…

Astronomers want to understand the Universe, from the Big Bang to the present day, and what the future will hold. In Leiden they focus on two key questions: ‘How did stars and planets originate’ and ‘How were galaxies and black holes formed in the young Universe?’ A new generation of telescopes – just…

Diverse types of exoplanets such as gas giants on close-in orbits (hot Jupiters) and young massive giants on wide orbits (super Jupiters), with no analogs in the Solar System, pose challenges but also opportunities to our understanding of planet formation and evolution.

Microbial rhodopsins are photosensitive pigments implemented in the growth and adaptation of a large population of microorganisms.

Promotor: M.A.G.J. Orrit

The thesis addresses the long-term dynamical evolution of hierarchical multiple systems.

Promotor: Prof.dr. T.J. Aartsma, Co-promotor: R.N. Frese

The zoo of detected exoplanets reveals both the uniqueness of our own Solar System and the complexity of planetary system formation, sparking fundamental questions about how planetary systems form and evolve.

Cutting-edge technological innovation for businesses and consumers, enabled by top-tier research on space and the quantum world.

In February 2026, Leiden University’s new Sport Centre opened on a prominent new site directly on the Campusplein. Its relocation brings sport visibly into the heart of campus life, with the outdoor fields seamlessly connected to the building. Substantially larger than its predecessor, the centre offers…

This dissertation is a collection of four research articles devoted to the study of Kummer theory for commutative algebraic groups.

About 15 km to the south of the ancient city of Petra, archaeologists from the University of Leiden have discovered an impressive network of ancient water conservation measures and irrigated field systems.

Three decades ago, cyber-diplomacy did not exist. The interest in Information and Communication Technology (ICT) as a vector of change in international relations was limited to a few mostly technical organisations, and a restricted number of states.

Promotores: P. Stevenhagen, A. Enge Co-Promotor: T.C. Streng

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”.

This thesis utilises the exceptional sensitivity and resolution of LOFAR to explore the low-frequency Universe, while simultaneously advancing the telescope's capabilities to enable new scientific discovery.