Promotor: Prof.dr. M. de Jong, Co-Promotor: Dr. A.J. Heijboer

Promotor: A. Achúcarro, Co-promotor: A. Boyarsky

In this work the reconstruction of a tau neutrino signal in the KM3NeT detector is discussed.

Promotor: M. de Jong, Co-Promotor: Samtleben

Physicists have studied the astrophysical neutrino signal as reported by the IceCube collaboration from a different angle with their ANTARES detector. The Milky Way centre was an obvious prime suspect to be a source, but this hypothesis is now only closer to debunked than confirmed. Publication in Physical…

Our current research focusses on the exploration of the Universe using the neutrino. This neutral, almost massless and only weakly interacting particle can open a window to the distant Universe and also dense regions from which photons cannot escape.

It is an established fact that the Standard Model has to be extended to explain the so-called Beyond the Standard Model (BSM) phenomena: dark matter, matter-antimatter asymmetry of the Universe and neutrino flavour oscillations.

Building the neutrino detector KM3NeT on the Mediterranean Sea floor has picked up pace. Five detection lines, each carrying eighteen detectors, have been sunk and installed, and the first measurement data are coming in, says neutrino physicist Dorothea Samtleben.

KM3NeT is selected as one of the ten top research facilities in NWO’s National Roadmap for Large-scale Research Infrastructure. Leiden physicist Dorothea Samtleben is the deputy program leader of Nikhef’s KM3NeT group.

The KM3NeT neutrino detector celebrates the installation of the first string of detectors in the Mediterranean Sea off the French coast. It will measure neutrinos’ spooky spontaneous change in flavor. Leiden physicist Dorothea Samtleben is closely involved in the project.

For the first time, scientists have traced back a high-energy neutrino to its source in space. It was produced by a so-called blazar—a supermassive black hole. Researchers from neutrino detector IceCube report this in Science. ‘This is a milestone for neutrino science,’ says physicist Dorothea Samtleben…

We simulate interstellar clouds with special plasma expansions and chemical reactions on icy dust grains to be measured in ultra-high vacuum setups. This provides the data necessary to guide and interpret astronomical observations and to model reaction networks in space. [Harold Linnartz]

Physicists, including Dorothea Samtleben from Leiden University, are building a giant underwater telescope to unravel the origin of neutrinos and to solve the mystery surrounding dark matter. The first detector has now been installed. Once it is finished, the telescope will be three cubic kilometres…

The Netherlands eScience Center has announced to fund a new Path-Finding Project led by Dr. Dorothea Samtleben from the Leiden Institute of Physics (LION). This project aims to make the processing of detection signals more efficient for the KM3NeT neutrino telescope, which is currently under construction…

This thesis revolves around the electronic spectroscopy of molecules in the laboratory and the search for the carriers of the diffuse interstellar bands (DIBs).

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

For only the second time ever, astronomers have linked a neutrino to an object outside our Milky Way. These observations were made using telescopes both on Earth and in space. The researchers, including Leiden astronomer Sjoert van Velzen, were able to trace the neutrino to a black hole that is devouring…

The Executive Board has appointed Professor Harold Linnartz as Professor of Laboratory Physics with effect from 1 June 2011. Linnartz has worked since 2005 as senior lecturer at the Leiden Observatory.

Promotor: A. Achúcarro Co-promotor: A. Boyarsky

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.

Stars and planets form within cold, dense clouds of gas and dust drifting through interstellar space. Although dust makes up only a small fraction of this material, it plays a key role in shaping the chemical evolution of these environments.

In my thesis I study Majorana fermions from three different perspectives. The first one corresponds to non-interacting Majorana fermions that, however, pose non-trivial topological properties. The second one corresponds to strongly interacting Majoranas and the third to relic neutrinos. No one knows…

Promotor: Prof.dr. H.V.J. Linnartz, Co-Promotores: S. Ioppolo, H.M. Cuppen

The Leiden Observatory has appointed a new professor. Selena Viti will hold a chair in Molecular Astrophysics. Viti will build a research group that combines different research techniques to unravel the secrets of local and external galaxies. ‘My main ambition is to change the way scientists interpret…

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

OB associations are loose groups of young, massive stars. They constitute the last stage of the massive starformation process, and the context in which new stars are formed.

This thesis takes steps toward understanding the interaction between gas-phase and solid-state molecules in star- and planet-forming regions.

Promotor: Prof.dr. S. Portegies Zwart

The 2015 Dissertation Prize of the Global Neutrino Network has been awarded to Tri Astraatmadja, who was part of the Leiden/Nikhef ANTARES group during his PhD research. Astraatmadja receives the award for his thesis 'Starlight between the waves: In search of TeV photon emission from Gamma-Ray Bursts…

Particle lab CERN gives the green light for the test phase of an experiment that aims to produce dark matter particles. Physicist Alexey Boyarsky is one of the initiators.

In the hunt for new particles, physicists look at ever higher energy particle collisions, moving the energy frontier. Some particles however are elusive not due to their high energy, but because they rarely interact. This raises a new barrier: the intensity frontier.

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 Leiden Science Young Talent Award celebrates a student who completed their bachelor’s degree with an outstanding thesis.

Leiden physicist Alexey Boyarsky, together with his colleagues from Lausanne and Copenhagen, has been awarded an ERC Advanced Grant to research an extension of the standard model of particle physics. The leading house of the project is the Technical University of Lausanne. 580.000 euro goes directly…

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…

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

The cosmology research line focuses on the theory of inflation in order to embed it in the microscopic theories of supergravity and string theory.

This thesis discusses the discovery potential of Intensity Frontier experiments.

A moon rock from the Apollo 17 mission, antique globes and the cosmos according to Wassily Kandinsky. Ewine van Dishoeck, Professor of Molecular Astrophysics, has put together an impressive exhibition at Rijksmuseum Boerhaave.

This master’s programme combines Physics with Data Science. You will learn how physics has its own tricks to deal with big data and how techniques from machine learning and deep learning can be applied to classical and quantum data. The first focus of attention is on classical data, including data mining,…

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

This thesis is a (biased) journey through very different topics in astrophysics: quasars and new populations of active galactic nuclei, gravitational waves from merging black holes, and protoplanetary discs around young stars.

Professor Simon Portegies Zwart and doctor Jeroen Bédorf had the honour to write for the IEEE Software magazine.

Simon Portegies Zwart, professor of Computational Astrophysics, uses computers to simulate the evolution of stars. We speak with him about his field and about the challenges of working with huge amounts of complex data.

The Tatiana Afanassjewa-lecture series was a series of public talks in Dutch that was started during the Covid-19 lockdown. The talks were given by Leiden physicists on wednesday evenings, intended for everyone with an interest in physics.