Program
Program
The workshop will take place on Monday March 23rd and Tuesday March 24th, 2026.
Launched in 2023, the Euclid space telescope is making a map of the extragalactic sky at unprecedented sharpness and sensitivity. The primary goal of the mission is to study the large scale structure of the universe with galaxy clustering and gravitational lensing. This talk will present the mission, the data it is gathering, and what to expect from the first data release later 2026.
The Vera C. Rubin Observatory is entering the first phase of its 10-year Legacy Survey of Space and Time (LSST), marking the beginning of an unprecedented exploration of the dynamic Universe. With survey operations approaching, the collaboration is transitioning from early data products toward full-scale cosmological exploitation of the dataset.
In this talk, I will provide an overview of the current status of Rubin data processing and early science, highlighting lessons learned from Data Preview 1 (DP1) and ongoing developments toward Data Preview 2 (DP2). These early data releases serve as critical testbeds for validating the end-to-end data flow, assessing image quality and shear measurements, and establishing robust photometric calibration pipelines.
I will then discuss how the collaboration is preparing for first-year cosmology analyses, including advances in weak-lensing shear validation, photometric redshift calibration, and systematic error mitigation. As precision requirements tighten toward the first cosmology-ready data release (DR1, expected from 2028 onward), coordinated efforts in simulations, calibration strategies, and cross-survey validation are becoming increasingly important.
Finally, I will highlight opportunities for synergy between Rubin and other major surveys, including Euclid, and discuss how joint analyses may enhance constraints on dark energy and large-scale structure.
This presentation aims to provide a broad overview of where Rubin stands today and how the cosmology program is being structured for the decade ahead.
After decades of being mostly confined to the local Universe, the study of gas dynamics in galaxies, via a variety of emission-line gas tracers, has now become a key tool of investigation across cosmic time. The rotation of the gas allows us to trace the distribution of matter, quantify the mass and shape of the dark matter halos and study galaxy scaling relations. At the same time, gas turbulence reveals the effects of stellar feedback and disc instabilities and provides clues on the formation of the stellar thin/thick discs.
I will present results on high-z rotation curves and velocity dispersions obtained through 3D reconstruction techniques of the emission-line datacubes. I will focus on ALMA observations of galaxies at z~4-5 observed in [CII] emission lines. These data reveal fast rotation and relatively-low gas velocity dispersions leading to typical V/sigma values of 5-10, similar to those of nearby spiral galaxies. Often, the fast rotations show the presence of mass concentrations that suggest a quick formation of stellar bulges. I will discuss how the widespread presence of such “cold” discs at z~4-5 are changing our understanding of galaxy formation at early times.
The caustic skeleton is parameter-free and mathematically rigorous formalism for tracing the formation history of the cosmic web from the singularities in the underlying dark matter flow. In this talk, I present our recent work on the construction of the caustic skeleton of the IllustrisTNG simulations, along with a detailed investigation of the properties of the embedded galaxies. By identifying the different web elements, I will shed more light on the bimodality of colour and star formation activity observed in cosmic surveys. I will here place emphasis on the multiscale nature of the cosmic mass distribution and its implications for the galaxy populations. Finally, I will address the formation time of the cosmic web and for the first time discuss the influence of the age of the present-day cosmic web on the embedded galaxies.
Lunch is included and on-site in the nearby cafeteria.
Can Machine Learning (ML) enable fundamental discoveries and help address long-standing challenges in cosmology? In recent years, the power of ML/AI—particularly deep learning—has been demonstrated in applications such as object classification, photometric redshift estimation, anomaly detection, enhanced simulations, and cosmological parameter inference.
After a brief overview of the past, present, and possible future of ML/AI in cosmology, I will discuss several examples, including field-level statistics for quantifying the cosmic web. I will also highlight the importance of dual training in astrophysics and ML/AI for the next generation of astronomers.
The Dark Energy Spectroscopic Instrument (DESI) collaboration is conducting an eight-year survey to collect the redshifts of more than 60 million galaxies and quasars. The principal aims of the survey are to test the physics of cosmic acceleration, gravity, dark matter, neutrinos, and inflation by charting the cosmic expansion history and the growth of the large-scale structure. In this talk, I will present some of the key cosmological results from DESI so far, with an outlook on the results to come from Data Release 2 (DR2).
With the LOw Frequency ARray (LOFAR), we can now study large samples of galaxies at 150MHz and below. The LOFAR Two-Metre Sky Survey (LoTSS) contains, in its latest data release, over 14 million galaxies, observing 88% of the northern sky. Such large samples allow us to study the population of radio galaxies in unprecedented detail. In addition, the deep fields within LoTSS, observed at both high and low resolution by LOFAR, and many facilities covering a large range of wavelengths, open a window into the high redshift universe. In this talk, I will give an overview of LOFAR's capabilities and surveys, as well as highlight the advances in our understanding of the evolution of radio galaxies that it has brought us. Specifically, I will show that the radio AGN population also undergoes cosmic downsizing, similar to their optical counterparts, and discuss the implications for supermassive black hole evolution across cosmic times. Finally, we will peer into the future of LOFAR2.0, and the upcoming programs that will provide even deeper insight into the radio galaxy population.
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The reception will feature refreshments as well as some light bites.
Overview of the Javalambre Physics of the Accelerating Universe Astrophysical Survey (J-PAS) in Teruel, Spain - the concept of the instrument, observation progress, and some of the cosmology-related studies using the data in Tartu Observatory.
This talk will outline the scientific and technical progress leading up to the mission’s first major delivery of cosmological data. We present the current status of the analysis pipelines, including advances in modeling, validation, and likelihood construction, as well as the integration of multiple probes such as galaxy clustering and weak lensing. Particular emphasis is placed on the robustness of the data products, the control of systematic uncertainties, and the coordination across the consortium to ensure scientific readiness. This first release will mark a key milestone, enabling unprecedented constraints on cosmological parameters and providing a foundation for exploring extensions to the standard cosmological model.
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I will gave a short overview of the new WEAVE spectroscopic survey facility for the 4.2m William Herschel Telescope and describe three of the five extragalactic surveys the WEAVE Survey is carrying out: the WEAVE-Clusters survey, exploring the impact of environment on galaxy evolution from dwarf to giant galaxies at z<0.5; the WEAVE-LOFAR survey, following up the low-frequency radio Universe at z>1; and WEAVE-QSO, mapping the Lyman-alpha forest at z~2-4.
I will give an overview of the 4MOST survey in general. In more detail, I will describe the extragalactic surveys dedicated to the cosmic web mapping in the nearby Universe. 4MOST is an ESO survey starting in spring 2026 and, in the next five years, will measure the redshifts of millions of galaxies in the southern hemisphere.
Lunch is included and on-site in the nearby cafeteria.
Just before we go for lunch, we will have a photo moment.
I provide a brief overview of studies of galaxy superclusters – the largest structures in the cosmic web. I discuss the definitions of superclusters, methods used to detect them, and their main properties, including their masses, shapes, morphology, and their evolution within the cosmic web. I also discuss superclusters as environments for galaxies, groups, and clusters.
In the local Universe, the richest superclusters form complexes and huge perpendicular planes whose sizes exceed several hundred megaparsecs. On these planes, superclusters form a quasi-regular pattern in which the characteristic distance between rich superclusters is 120–140 h−1Mpc. I will discuss possible origin of this pattern. It remains an open question whether the presence of such structures can be fully explained within the ΛCDM cosmological model.
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Soon to be entering its fifth year of observations, the James Webb Space Telescope has revolutionised our understanding of early galaxy evolution. In this talk I will discuss our view of the new redshift frontier, the galaxy populations hidden from JWST’s predecessors and the diversity of galaxies present in the early Universe. Throughout, I will highlight the critical success of JWST’s spectroscopic instruments and describe how these observations are unlocking unprecedented insights into the star formation histories, chemical composition and dust properties of galaxies across cosmic time. Furthermore, I will introduce the new puzzles JWST is presenting us and will conclude by discussing upcoming observations designed to address these questions.
We will have a guided tour through the botanical gardens, for those who indicated they would like to participate. Your entry to the botanical gardens is complementary.
For those who are interested, Tuesday night there will be a public lecture to attend in the city center.
When ChatGPT launched in 2022, it showed the world that computers can write poetry, generate images, and hold conversations, but in mathematics it still struggled with simple logic puzzles and long division. Three years later, the picture looks very different, with AIs winning medals at the International Mathematical Olympiad and mathematicians publishing papers that credit AI assistants with suggesting key ideas. What happened, and how impressed should we be? Johan Commelin explores the rapid evolution of AI in mathematics, combining concrete examples with historical context. We trace the path from early experiments to recent breakthroughs, highlighting both the strengths and limitations of these systems. Finally, we consider what the future might hold in five or fifty years, and discuss how the mathematical community can help shape these technologies while preserving its core intellectual values.
The Johann Bernoulli lecture is an annual lecture hosted by the Johann Bernoulli Foundation, that aims to bring mathematical topics to the wider public. This year, Johan Commelin will speak about whether or not machines have the ability to do mathematics. The lecture is held in the ornate aula of the academy building in downtown Groningen, and admission is free of charge, although registration is required. For more information, such as the abstract and registration link, click here.
The Johann Bernoulli lecture is not a formal part of this workshop.